CPA vs CPI: Which One You Should Start With in 2020

If you are about to embark on your affiliate marketing journey, you have most likely encountered some of the most popular abbreviations such as CPA, CPL or CPI.

These might sound confusing at first, but I guarantee you – two weeks in advertising them, you will know everything there is to know.

Most of the three letter abbreviations, starting with C, in affiliate marketing, are the different payout or agreement models that you can have with an affiliate offer.

For instance, CPA stands for Cost Per Action, and it means that you are getting paid once a visitor performs a certain desired action via your affiliate link such as signing up or entering their email address.

CPI, on the other hand, stands for Cost Per Install, which intuitively means that you get paid when someone installs a program, or in most cases an app, via your affiliate link.

Let’s dive into more detail, because in this article we are going to take a closer look at what those are, what are the typical offers for both types, and which you is better for you as a beginner in affiliate marketing.

What is CPA / Cost Per Action? 

After the brief introduction you are probably wondering what the Action stands for. That’s okay, because this might be confusing at first and there’s no actual definition for CPA – it’s more like the largest category because it includes so many different methods.

CPA could be considered if you are advertising a software, and asking somebody to get a free trail on it. Or another case would be asking for their email address or phone number.

Examples of CPA Offers

A popular vertical that’s primarily CPA is the sweepstakes one, in which a person has to submit some kind of personal information in order to participate in a raffle for a given product or incentive.

Sweepstakes is among the most popular and established verticals for affiliate marketeers, and the majority of the offers on it are CPA, while there are some others like PIN Submits, CC Submits, etc.

Another vertical that’s heavily using the CPA model is the dating one, in which you get paid once a person signs up on the dating website.

You will later on find out about those two terms – SOI and DOI, and I will explain briefly what those two mean.

SOI, that stands for Single-Opt-In, means that you get paid once a visitor from your affiliate link signs up or submits their email address, and is not required to do any further actions.

DOI, that stands for Double-Opt-In, means that usually there’s another step for signing up involved such as an email address confirmation, or a SMS confirmation.

SOI offers are easier to convert, but the payouts are generally significantly lower than DOI offers. For beginners, it is recommended to start with SOI, because they can be advertised with a lower budget, and then move onto DOI offers once they have figured out what works and what doesn’t.

Additionally, if you have two similar offers, but one is SOI and one is DOI, you can use the SOI one for testing and creating your blacklists and whitelists, and then moving onto DOI once you have found the winning combination between target audience, ad creatives and landing page.

What is CPI / Cost Per Install?

Cost Per Install is pretty self-explanatory in terms of what it means, but still let me give you some examples of how it can be used.

For instance, if you are promoting a PC application, the user would need to download it, and install it onto their computer. Almost the same goes for mobile applications, except they would be downloading it from the given app store.

Examples of CPI Offers

CPI offers are typically games and social apps when it comes to mobile devices. However, on PCs it’s primarily antivirus software, VPNs and other utilities.

The VPN vertical on mobile is also huge, and it’s actually a great place to try once you are a bit more advanced.

These offers also frequently allow incentive traffic, which means that you can have a download or content locked, so you can give your visitors an incentive to install this app.

This “incentive” method is quite unpopular with most verticals as it usually attracts unwanted and hard to retain users.

Fortunately, there are also some really good offers that you can be promoting with the CPI method, especially for VPNs.

People need browsing privacy, and this is the perfect way to give it to them, and also make some money.

My suggestion here would be to promote only software you would download yourself, as it would have a higher conversion rate.

Another big vertical in the CPI niche are games, and actually the best way to promote them (and I have personally done this) is via social media stories – Facebook, Instagram, Snapchat.

If you could make an attractive gameplay video of the specific game, and add your own Call to Action like “Download now for free” or “I am so addicted to this game I can’t stop playing“, or something in the sorts.

You would also have to keep in mind that you should pick an interesting moment in the game, where there’s some sort of puzzle or challenge to pass, so that the viewers feels the need to do it themselves.

The greatest thing about CPI is that you are mainly promoting free to download apps. Of course, most of them are going to request that the person does an in-app purchase, especially the VPN ones, but you don’t really care about the apps user attention as long as it is attractive enough to make people download and install it.


The truth is there’s no right or wrong question. Even if you are a total beginner both options are open to you, and they can be very lucrative.

Which one is harder? Perhaps that would be the CPI cost model, but that shouldn’t stop you from trying it, in case you have found a good offer that it is converting right now.

There’s an abundance of Spy Tools that you can use like AdPlexity or Mobidea SpyTools to see what ads your competitors are running.

This way, you can see which ads have been running the longest, and know what’s converting subsequently.

CPA definitely has quite the bigger abundance of offers, compared to CPI, where the number of offers is limited, and the number of actual good offers is even less.

What I would recommend to you is just doing some scouting for offers, you can even get a list of offers from both cost models, do an analysis of which ones are converting well right now, and then start testing.

That’s the only way you are ever going to see some results – whether positive or negative. They will most likely be negative, but that shouldn’t discourage you.

In fact, here’s a list of the most popular reasons your ads aren’t converting well:

  • Your offer is just not converting
  • Your ad funnel is inconsistent or unclear
  • You are targeting the wrong zones or audiences
  • Your ad creatives need improvement
  • You are using the wrong traffic source

All the listed things above happen to everybody, and it’s important to identify which one of them is the culprit by testing and testing and testing.

So, if you have decided to go on the affiliate marketing journey, my recommendation for you is to just dive in, but make sure you rely on data and not luck.

You can also read 5 Must-Have Skills To Be Successful in Affiliate Marketing, which can serve you as kind of a to-do-list for before starting affiliate marketing if you are a beginner.

Written by Asen Levov

I am a startup founder with years of experience in web development and digital marketing. I have been doing affiliate marketing since 2015, primarily performance. Started Ad Specto to share my story and my knowledge with the world. Founder @SketchCoWorking @AdSpecto

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