Best 4 Channel Audio Interfaces

Top 9 Best 4 Channel Audio Interfaces (June 2024)

The Best 4 Channel Audio Interfaces (June 2024)

The best 4 channel audio interfaces offer fantastic opportunities to record high quality audio from several sources with minimal latency.

Audio interfaces range from large 'rack' styled devices through to pocket sized incredibly compact and durable audio interfaces. Some come with full colour LED/LCD displays for input and output levels, others offer portability by being powered by batteries.

Whether you're looking to record a keyboard, guitar or vocals, the best way to setup your recording station is to plug into your computer and make tracks via a 4 channel audio interface. Whatever type of audio interface you're looking for we've tried to find the audio interfaces with the best features. While still being considered a great four channel audio interface.

Perhaps 4 channels isn't enough? We've got a buyers guide that covers the best 8 Channel Audio Interfaces.

The Best 4 Channel Audio Interfaces Buyers Guide (June 2024)

  • 1. RME Audio Fireface UFX II
  • 2. Antelope Audio Antelope Zen Tour
  • 3. RME Audio Interface (BABYFACEPRO)
  • 4. Focusrite Scarlett 18i8 Audio Interface
  • 5. MOTU M4
  • 6. Native Instruments Komplete Audio 6
  • 7. Focusrite Scarlett 4i4
  • 8. Steinberg UR242
  • 9. BEHRINGER UMC 404HD Audiophile
RME Audio Fireface UFX II Image

RME Audio Fireface UFX II

  • ✔ Ultra-low latency operation with USB and FireWire
  • ✔ All inputs and outputs can be used at the same time
  • ✔ Direct USB Recording
  • ✔ Best low latency performance

This is one of the most reliable and fully featured interfaces on the market.

RME Audio Fireface UFX II - Read Review See The Latest Price On Amazon Now

RME's best-of-class universal audio interface is a worthy successor to the Fireface 800, the "king of the hill" for many years. It offers the most natural, transparent audio path of any interface on the planet: The UFX II combines its superior A/D converters with RME's unique low-latency ASIO2 and Core Audio drivers. It is a high-end professional interface with a USB 2.0 connection. The Fireface device provides a wide range of connections, including FireWire, optical and coaxial digital, analog xlr, and MIDI. It is an interface which can be used in all areas of music-making, from recording to live performance.

The Fireface UFX II is a 16-In/16-Out USB 2.0 interface with two mic preamps, two Hi-Z instrument inputs, MIDI I/O and S/PDIF I/O. The Fireface device comes with the DIGICheck metering/routing/mixing/mastering software to get you started right away. It comes equipped with two analog microphone preamplifiers with three configurable inputs, two analog line inputs, two analog line outputs, and MIDI I/O.

Featuring the latest technology and an incredible ease of use, the RME UFX II is the new top model in the Fireface UFX series of USB interfaces. Perfect for any application that requires the highest quality audio. The Fireface UFX II is the ultimate replacement to the original UFX for the ultimate high-end audio experience on Mac and PC.

Antelope Audio Antelope Zen Tour Image

Antelope Audio Antelope Zen Tour

  • ✔ 24-bit, 192 kHz audio and Antelope’s signature flawless conversion
  • ✔ Guitar amp modeling and effects processing with virtually 0 latency
  • ✔ Touchscreen control panel
  • ✔ 32 channels via Thunderbolt and 24 channels on USB

If you want a high-quality audio interface for studio, rehearsals and gigs you have to look at this.

Antelope Audio Antelope Zen Tour - Read Review See The Latest Price On Amazon Now

The Antelope Audio Zen Tour is a portable USB Audio Interface that contains Antelope's award-winning 24-bit / 192 kHz Analog-to-Digital converters and Digital-to-Analog converters, as well as Zero Latency Monitoring technology, making it the go-to interface for traveling musicians, DJs or anyone who is on the road. The Zen Tour is an interface with performance, versatility and ease of use unsurpassed in the industry. Antelope's innovative design eliminates the need to make complex choices and trade-offs. With the Zen Tour, you get it all. Streamlined control and simple operation is further enhanced with exclusive Plug-And-Play presets, which are optimized for the most popular audio recording and live performance applications.

As a compact USB audio interface that includes microphone preamplifiers with adjustable gain, headphone amplifiers. As well as an advanced DSP mixer. The Zen Tour is a complete solution for recording a band, singer/songwriter, or solo musical performance. The Zen Tour's input channels are loaded with premium-grade components that are hand-picked from the Antelope Audio sound bard for their sonic purity and transparency.

The Zen Tour has an extremely powerful yet highly intuitive design that makes recording and mixing extremely easy. It is the perfect choice for recording musicians, vocalists, and sound engineers. It is designed with the professional musician in mind, who needs to capture audio in the most straightforward way possible.

RME Audio Interface (BABYFACEPRO) Image

RME Audio Interface (BABYFACEPRO)

  • ✔ Extremely portable
  • ✔ Bus-powered or mains powered
  • ✔ Premium quality product
  • ✔ Pricey when considering input/output capacity

Ultra portable and a customer favourite

RME Audio Interface (BABYFACEPRO) - Read Review See The Latest Price On Amazon Now

The Babyface Pro by RME is one of the most portable audio interfaces that we’ve featured on the list, besides from the Apogee Duet of course.

Despite the unit’s size, it has a range of connectivity ports, including XLR inputs/outputs, Line, MIDI & ADAT inputs/outputs, making it very versatile for those who require several input/output types.

Additionally, the unit is housed within an aluminum chassis, and runs on either bus-power or an external power supply… All of which is totally up to yourself.

Not only have RME created a well-built audio interface, but they’ve especially prioritized their efforts on the internal circuitry, with it featuring the latest generation of low latency AD/DA converters, in combination with RME’s ‘Steadyclock’ technology, which helps further reduce noise, helping create a noise-free, clear output sound.

Overall, with all that being said, the RME Babyface Pro is ideal for those who want a portable audio interface, with a wider selection of inputs/outputs than the similarly sized Apogee Duet.

  • Mac & PC & iOS devices
  • Supports all major DAWs
  • Highly reputable brand
  • 24-channel mobile solution
  • A very portable audio interface
  • Aluminum chassis for effective protection
  • High-quality internal circuitry for low-latency
  • Includes software
    • RME’s TotalMix FX
  • Warranty: 2-Year Manufacturers Warranty
Technical Specs
  • USB 2.0/3.0 connectivity
  • 2 XLR inputs
  • 2 XLR outputs
  • MIDI input/output
  • ADAT input/output
  • 2 headphone line outputs
  • 24-bit/192 kHz resolution
  • 20 Hz – 35 kHz Frequency Response
  • Power adapter or bus-powered
  • 48v Phantom Power
  • Premium quality product
  • Extremely portable
  • Bus-powered or mains powered
  • Very portable
  • 2-year manufacturers warranty

Focusrite Scarlett 18i8 Audio Interface Image

Focusrite Scarlett 18i8 Audio Interface

  • ✔ Highly reputable brand
  • ✔ One of the best selling audio interfaces
  • ✔ iPad, iPhone & iPod compatible
  • ✔ Extremely impressive technical specs (192 kHz/24-bit)

The next iteration of this best-selling, award-winning Scarlett series.

Focusrite Scarlett 18i8 Audio Interface - Read Review See The Latest Price On Amazon Now

The Scarlett 18i8 is the third generation in the iteration of this best-selling, award-winning Scarlett series.

Focusrite has been creating affordable interfaces, which exude premium audio quality since they started the Scarlett series, and the 3rd generation is definitely an interface that packs a punch!

It’s one of the more affordable 8-channel audio interfaces that we’ve featured on the list, yet it provides superior sound quality compared to other interfaces, as it offers 192 kHz/24-bit sound resolution. Not to mention, the unit has recently been released, and they’ve redesigned the preamps for it.

This is a great audio interface from industry favorite Native Instruments. It comes with an extremely clean and symmetrical design making it aesthetically pleasing with any studio setup. This interface features a wide range of connectivity for its price. It features plenty of outputs and inputs, so you should be able to connect it to almost any home studio setup with ease. This will allow you to plug in your studio monitors and your subwoofer with no problem. An excellent interface from one of the best companies in the industry. This interface is a must have for beginner producers looking to step up their production quality.

Construction of the Audio 6 is reassuringly solid. Weighing in at around 1.9 lb (850 grams), the internals feel suitably protected in a rugged but attractive black and silver metal chassis. Once unboxed and we’d finished admiring the overall aesthetic our attention was quickly drawn to the rather huge analog volume control that’s centered on the glossy top panel. In practice, the utility of this oversized dial can’t be overstated and we loved just how convenient it became to make volume adjustments with barely a second thought. The remaining regular sized knobs are made of rubber and turn smoothly, and the various buttons give a satisfying click when pushed. Rubber feet on the bottom of the unit provide stability while protecting the chassis and your desk. Overall we were impressed with the build of this interface.

The unit also includes MIDI input/output, optical input and a SPDIF input/output.

On the brushed aluminum front panel you’ll find two analog XLR/TRS combo inputs for microphones and instruments, each with a complementary gain control and a standard line/instrument switch. XLR retaining locks add a small professional touch. Moving along we find separate controls for monitor and headphone volume. Headphone input, a headphone source switch, a mono switch, and a direct monitoring switch for zero latency monitoring.

Located on the rear are a further two 1/4″ TRS inputs and four balanced 1/4″ outputs, MIDI in/out sockets (for those with legacy synths and drum machines) and digital stereo input and output (SPDIF / RCA). Finally for the rear, we find a USB socket, and a 48V phantom power switch enabling you to connect condenser microphones.

Preliminary browsing through user reviews of the Komplete Audio 6 seemed to suggest some occasional problems with the drivers provided for the interface. We forged ahead with installs on a Windows 10 desktop and a 2015 Apple Macbook Pro, having downloaded the most recent drivers from Native’ website. Installation on Windows 10 of driver version 4.2.0 was quick and painless, resulting in a straightforward settings panel being installed. On our Macbook we’re running OS X 10.11 (El Capitan) which does not appear to be officially supported by the most recent Mac OS X driver, a Native Instruments representative confirmed however that internal testing has revealed no significant problems and indeed installation on our Macbook was as expected with no issues to speak of so far. Stability of the drivers was not in question with us suffering no dropouts, popping or hissing on either operating system.

Audio quality from the Audio 6 is clear and punchy and on par with competition in its price range. We found the gain controls to provide more than enough volume for quiet microphones. However noted that the headphone output is not quite as blaringly loud as some other interfaces. Volume should be sufficient for general use but the maximum level did fall just a little short of our expectations. In contrast, we were thoroughly impressedwhile recording at the interfaces limit of 24-bit/96 kHz. The level of latency experienced was minimal.

Additionally, it includes a wide range of free software, including Pro Tools, Ableton live, etc, so this unit is great for those who potentially don’t already have a DAW or plugins.

The inclusion of four ins and outs plus MIDI in and out combined with the impressive design. It’s rugged construction and solid performance make this a top contender in this price range. Highly recommended. Overall, as you might be able to tell, we particularly like the Scarlett 18i8, and there’s a reason why this is the 3rd generation and it’s one of the best selling audio interfaces of all time.

  • Mac, PC, iPad, iPhone, iPod
  • Supports all major DAWs
  • Best-selling audio interface
  • Extremely reputable brand
  • New Technology – Recently released
  • Sleek design & well-built metal chassis
  • Highly portable
  • Newly designed, high-quality microphone preamps
  • iPad, iPhone, iPod device compatible
  • Software included:
    • Avid pro tools, Focusrite creative pack, Ableton live lite, Splice sounds (3-month subscription), XLN audio addictive keys, Softube time and tone bundle. Not forgetting the Focusrite red plugin suite, plugin collective and control.
  • Warranty: 2 Year Manufacturers Warranty
Technical Specs
  • USB Type C connectivity
  • MIDI input/output
  • 4 XLR/TRS combination inputs (on the front)
  • 4 TRS inputs (on the back)
  • 4 TRS outputs (on the back)
  • 2 TRS headphones outputs (on the front)
  • Optical input
  • SPDIF input/output
  • Supports all major DAWs
  • 24-bit/192 kHz resolution
  • 48v Phantom Power
  • Highly reputable brand
  • One of the best selling audio interfaces
  • Brand new generation (new technology)
  • iPad, iPhone & iPod compatible
  • Extremely impressive technical specs (192 kHz/24-bit)
  • Includes lots of software

MOTU M4 Image


  • ✔ Monitor Live Inputs At Super Speed
  • ✔ Full Color LCD Display
  • ✔ Works With Mac And PC
  • ✔ Loopback Computer Output Back To The Computer

A 4 channel audio interface with a usb-c connection and great sound quality. It is reliable and well made.

See The Latest Price On Amazon Now

MOTU is a company that has been making professional audio equipment for over 30 years. The M4 is MOTU's newest product that can be used with any computer with USB-C or Thunderbolt 3 ports. The MOTU M4 is a 4 channel audio interface. It is reliable, has great sound and well made.

The MOTU M4 is a perfect choice for those who are looking to improve their home studios. It has a high-quality sound and allows you to record four channels at the same time. The interface has been made to be reliable and well made which makes it last longer than other interfaces on the market.

This audio interface has four channels that can be used for recording or playback of any system sound. It is compatible with Mac and PC and provides a very good quality of sound. This audio interface also supports the latest USB-C connectivity and it comes with great features such as a headphone output on each channel for monitoring purposes, MIDI I/O ports, digital I/O ports, analog I/O ports, phantom power switch on each channel as well as an input gain knob per channel for adjusting the input signal strength to the preamp stage.

The M4 features four channels of ultra-low noise preamps with +48V phantom power for use with condenser microphones, a high-performance analog to digital converter, and MOTU’s world renowned digital signal processing. It also features two headphone outputs with independent level controls, monitor speaker outputs with level control, MIDI input and output ports, S/PDIF digital input and output ports, word clock input and output ports, AES/EBU digital inputs and outputs.

Native Instruments Komplete Audio 6 Image

Native Instruments Komplete Audio 6

  • ✔ High-quality pre-amps
  • ✔ Low-latency performance
  • ✔ Mono input switch for recording vocals or guitars
  • ✔ Direct monitoring for live

This is a great audio interface from industry favorite Native Instruments.

Native Instruments Komplete Audio 6 - Read Review See The Latest Price On Amazon Now

Audio interfaces have been getting smaller and smaller in the last few years, with the introduction of the mini-jack. However, a low quality sound is still being produced through these mini-jack devices. The Native Instruments KA6 is a high quality interface that has been designed and manufactured to be used with a professional studio.

Native Instruments KA6 is designed to deliver a studio quality audio experience to your computer. It is designed by Native Instruments, a company that has been providing musicians with the best in music creation equipment for years.

The Komplete Audio 6 is Native Instruments' most affordable interface ever. The new interface features the same high-quality preamps as the older models. As well as a host of upgrades that make it a bit easier to use.

The Native Instruments KA6 is the perfect solution for your home studio. It is easy to use, sounds great, and works with virtually any piece of recording software, such as Pro Tools. The audio interface is equipped with two microphone inputs with analog compression, phantom power, and high-quality 24-bit converters. It is also features stereo inputs for your instruments, a pair of balanced line outputs, and a single headphone output.

When it comes to recording, the quality of your recording equipment is important, especially if you want to record high quality audio. Native Instruments KA6 is used by professionals to record their tracks. It has a wide range of uses in any home recording studio. It is a perfect way to set up a home recording studio for those on a budget.

Focusrite Scarlett 4i4 Image

Focusrite Scarlett 4i4

  • ✔ High-performance converters
  • ✔ Mix at up to 24-bit/ 192kHz
  • ✔ USB-C powered device
  • ✔ Compatible with Windows, Mac and iPad

A great competitively-priced option with plenty of connectivity.

Focusrite Scarlett 4i4 - Read Review See The Latest Price On Amazon Now

Focusrite’s Scarlett USB interfaces have traditionally combined excellent sonics and audio flexibility at affordable price points, and the third generation units keep up the good work.

All units in the range have received physical and technical upgrades, with improved preamps (now up to 56dB gain), balanced connectivity throughout, and the inclusion of Focusrite’s ISA transformer preamp emulation option (Air). On the bus-powered Scarlett 4i4 you get two mic/line/instrument inputs with gain, two line-level TRS inputs and four TRS outputs.

The 4i4 supports Focusrite’s Control application, which means that a number of settings can only be made in the software. The app also handles low-latency monitoring.

As we’ve come to expect from the Scarlett series, the sonics are neutral and the drivers reliable. The Air option tilts the frequency response towards high frequencies, and this can be great for taming undesirable proximity or adding high frequency lift.

With a decent software bundle included, this is a solid upgrade and a great affordable audio interface.

Focusrite’s Scarlett USB interfaces combine excellent sonics and audio flexibility at an affordable price point, and the third generation units have just landed. 

Up for review we have two of the mid-sized units (the 8i6 and 4i4) from a range that starts with the pocket-sized Solo, and tops out at the impressively equipped 18i20. All units in the range have received a physical and technical upgrade, with improved preamps (now up to 56dB gain), balanced connectivity throughout, and the inclusion of Focusrite’s ISA transformer preamp emulation option (Air). There’s now a slicker front panel with LEDs and the halo-style input level meters sitting below a shiny surface. Meanwhile, all units now use USB Type C connectors, although for the foreseeable future will ship with Type C to Type A cables. Finally, Focusrite is rolling out a new onscreen onboarding process that guides you through the setup from the moment you first plug in.

Looking specifically at the review units, both gain a couple of extra inputs over their predecessors (the 2i4 and 6i6). So, for the 4i4 you get two mic/line/instrument inputs with gain, two line-level TRS inputs and four TRS outputs. The 8i6 also has two mic/line/instrument inputs with gain, and gets four line-level TRS inputs, four TRS outputs and stereo S/PDIF in/out. Both units include MIDI in/out. For headphones, the 4i4 has one front panel output with level and the 8i6 two outputs with individual level. The larger interface requires an external PSU which, though understandable, is moderately annoying given it’s pretty compact. The smaller 4i4 is USB bus-powered.Both the 4i4 and 8i6 support Focusrite’s Control application, and this means that a number of settings including pad, line/Hi Z instrument selector, and the Air option mentioned above can only be set via the software. The app also handles low-latency monitoring, so there’s no direct monitoring knob as per the 2i4, although it’s worth noting that the 3rd Gen 2i2 and Solo interfaces continue to use this system. Whether you view this as extra flexibility or unnecessary complexity is personal preference, but I like the software option, particularly when you take into account that there’s an accompanying nifty iOS app that effectively adds in remote control capabilities as well. A further positive is the monitor mix system which allows easy creation of low latency mixes for each output stream. Finally, both interfaces support Focusrite’s Loopback feature, whereby a further mix panel allows you to quickly route inputs, DAW outputs or a custom blend of both back into the DAW.

As we’ve come to expect from the Scarlett series, the sonics are neutral and the drivers reliable, and both units operate at up to 192kHz. The Air option tilts the frequency response towards high frequencies, and this can be great for taming undesirable proximity or adding high frequency lift. There’s also a decent pack of bundled software including Ableton Live Lite 10, Pro Tools First Focusrite Creative Pack, Focusrite Red 2 and Red 3 plugin suite, Softube Time and Tone bundle, XLN Audio Addictive Keys and Focusrite Plug-In Collective. This is a solid refresh and both review models deliver a noticeable upgrade on predecessors.

Steinberg UR242 Image

Steinberg UR242

  • ✔ Compatible with mac and windows
  • ✔ MIDI input/output & iPad connectivity
  • ✔ USB2.0
  • ✔ Some complaints regarding the latest mac software compatibility

Steinberg is a well-known brand that caters to professional musicians around the world.

Steinberg UR242 - Read Review See The Latest Price On Amazon Now

Steinberg is a well-known brand that caters to professional musicians around the world. The UR242 takes the tops spot on our list as it proves itself to be a great value audio interface and an all-round workhorse.

This audio interface is an ideal piece of kit if you are planning on doing some home recording on a budget of $300 or less. It features a dedicated TRS headphone output, combined microphone/TRS instrument inputs, monitor inputs and MIDI inputs. You also get a copy of Cubase which is one of the most popular DAW’s on the market today.

Steinberg UR242 is an external sound card for both audiophiles and recording enthusiasts. This interface is compatible with both PC and Mac. The UR242 makes it easy to record guitar, vocals, percussion and other instruments from the comfort of your home studio.

This is a relatively inexpensive USB audio interface from a world-famous brand and would be a solid purchase for any home studio.

The UR242 offers musicians and producers far more than just a portable I/O device, or even an audio interface; the UR242 is a mobile production solution. That’s because it combines fantastic-sounding I/O and durability with advanced DSP-based FX that can be used with your DAW software, and that at a price point that is still easily affordable.

BEHRINGER UMC 404HD Audiophile Image

BEHRINGER UMC 404HD Audiophile

  • ✔ Audiophile 24 - bit/192 kHz resolution
  • ✔ Midas designed mic preamplifiers
  • ✔ Compatible with popular recording software
  • ✔ USB 2.0

Easily one of the most versatile audio interfaces you can find on a tight budget.

BEHRINGER UMC 404HD Audiophile - Read Review See The Latest Price On Amazon Now

The Behringer UMC404HD is a great audio interface when you want to record high quality audio. This interface allows you to record up to four tracks simultaneously. You can plug in your microphone into the XLR input or you can plug in your guitar or bass directly into this device. This audio interface has a built-in mixer and you can set the volume of each channel individually.

The BEHRINGER UMC404HD is the perfect interface for your computer-based home studio. The UMC404HD is a low-noise, high-headroom, true analog-to-digital/digital-to-analog converter. It delivers pristine 24-bit/96kHz audio quality and plenty of connectivity. Two combo mic/instrument inputs with XLR/TRS connectors and a hi-Z input on the front panel are complemented by two balanced TRS outputs. The UMC404HD has both digital (S/PDIF) and analog (RCA) outputs and comes with a copy of Tracktion 2 Music Production Software for video-free recording and editing.

It provides four studio-quality microphone preamps with phantom power and excellent RFI rejection, plus four balanced analog outputs with Level control for the ultimate in recording flexibility. The UMC404HD offers a complete professional recording studio at a budget price. A powerful DSP (digital signal processor) engine works with new digital converters for superior audio quality. With its ultra-low latency, you can capture audio with no delay, allowing you to record and monitor with software effects in real time.

More Information Regarding 4 Channel Audio Interfaces (2024)

What is a 4 Channel Audio Interface

In essence an audio interface allows you to take audio signals and pump them in and out of your computer. The decision on which one is right for you simply comes down to a combination of your budget and how you like to work. Simplistic models exist that simply convert analog audio signals to digital audio signals on the way to your computer. This is because your computer will have software such as pro tools that is able to understand digital audio signals. Allowing you to layer, manipulate and refine the sound and then pump out to a speaker or amplifier. The audio interface will convert your digital audio signals back to analog signals on the way out of your computer. This way the speaker is able to play the sound for you to hear. These types of audio interfaces are known as AD/DA (Analog to Digital/Digital to Analog) converters

Connection Types

4 channel audio interfaces come with all sorts of connection types allowing you to connect to your computer via USB, thunderbolt & firewire to name a few. USB is the most popular and widely used mainly because it comes in many different forms ranging from Type-A, 2.0, & Micro USB through to the latest Type-C connections. Thunderbolt connections are the fastest. You'll find these are used on some of the more modern and high end 4 channel audio interfaces available on the market.


The price of top quality 4 channel audio interfaces has fallen dramatically in recent years. This is great news if you're looking to get hold of a device that will give you a fantastic sound without costing the earth. This is because many brands have taken their previous generation 4 channel audio interface models and repackaged them. Usually with some modern nuances to create a budget model of their current range. Don't be put off by this, these audio interfaces are still great value. They might not have all the latest bells and whistles but they get the job done. Which means you don't need to pay substantial amounts of money for them.

Depending on what you want to achieve, you'll priorities different features when finding the best audio interfaces for your situation. If space is an issue you'll look for a small to medium sized interface that provides you a great experience and end result while not taking up a large portion of your limited space. If you're in need of a portable audio interface then you'll probably rule out any rack mountable models. Instead you'll be looking for small battery powered options.

Inputs & Outputs

4 channel audio interfaces come with a range of inputs and outputs. Some will have line inputs, mic preamps, headphone outputs, mic inputs & many other inputs and outputs. Make sure the model you consider has what you need. If you're kitting out a home studio then you'll be looking for the best audio interface which features (such as phantom power) the inputs and outputs you need at an affordable price.

Some of the best audio interfaces on the market come with software as part of the package. Pro tools is a popular editing software that we've seen offered as part of audio interface packages in the past. Purchasing an audio interface that comes with a reputable editing software is a great way to justify paying more for your audio interface because you're saving money elsewhere.

Best Guitar Equipment

Affiliate Disclosure is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for website owners to earn advertising fees by advertising and linking to, and any other website that may be affiliated with Amazon Service LLC Associates Program.