Case Study: Similar Signup Cost, Yet 19% Cheaper Per Deposit

Case Study Breakdown · Issue 10

Hi, I’m Peter.

This issue’s case comes from the PropellerAds official blog. A media buyer running a gaming offer ran Paid Social and Popunder in the same Southeast Asian country, with the same setup, for 30 days, and compared only one thing: how much each deposit cost.

Issues 4 and 8 both covered Paid Social. This is the fourth time I’m looking at it with a gaming offer, and this time the test was designed as a clean A/B test.

Test setup

Data comes from the PropellerAds official blog (September 2, 2026). This article is published with PropellerAds’ authorization.

01 Only one thing changed

The test set out to answer one question: when the more expensive Paid Social traffic goes into a deposit funnel, is it actually worth it?

To keep the answer clean, the media buyer set a few rules:

Same offer; same campaign settings, with the same devices and pricing model; same period; same country.

The only difference was the traffic format, Paid Social on one side and Popunder on the other, and in the end only the cost per deposit was compared.

The media buyer pays for impressions, the offer pays out on deposits, and there is a signup step in between.

So what this issue looks at is how much was spent at each step as the money moved from impression to deposit.

02 Look only at signups and you’d think they’re about the same

First, the signup step:

Paid Social’s price per thousand impressions is 1.5 times Pop’s, yet its cost per signup is about the same as Pop’s.

If the test had stopped here, it would be hard to conclude that Paid Social is worth paying more for.

The difference shows up in the next step: deposits.

Of the people who signed up and then went on to deposit, Paid Social had 59.3% and Popunder only 51.2%.

Take 100 signups from each: Paid Social spent $587 and got 59 deposits; Popunder spent $624 and got 51.

The result:

Paid Social: 7,375 deposits, $9.89 each

Popunder: 17,254 deposits, $12.20 each

The signups cost about the same, but more of those people paid.

My read: the people Paid Social brings in are more willing to engage with ads to begin with, so the extra CPM pays off at the deposit step.

03 The further along, the bigger the gap

Popunder has more deposits in total because its volume is four times Paid Social’s. Counted per the same number of impressions, Paid Social’s deposits are close to double Pop’s.

Paid Social got only 19% of the test’s impressions but 30% of all deposits.

Now the timeline:

In the first half of the month, Paid Social’s cost per deposit was 8.2% lower than Pop’s; in the second half, 26.3% lower.

The reason is the signup-to-deposit rate: Paid Social rose from 51.7% to 66.1%, while Popunder stayed around 51% and barely moved.

Over the 30 days, Paid Social’s deposits were cheaper on 25 of them.

04 The full comparison

Same offer, same country, same 30 days:

Impressions cost more, signups are about the same, and deposits are cheaper.

05 It’s not either/or

The official conclusion: Paid Social costs more per thousand impressions, but each thousand impressions brings 1.8 times the deposits Pop does, and on an offer paid per deposit, each deposit came out 19% cheaper.

But that doesn’t mean one traffic source is better by nature, and it doesn’t mean you have to pick one of the two every time.

Oleksandr Shovkun, head of the sales team at PropellerAds, said:

Paid Social is premium traffic. The audience is filtered, and in some countries the volume will be limited.

If your project is still in its growth phase, I don’t recommend treating Paid Social and Popunder as an either/or choice. The best approach is to run them together: Paid Social brings high-quality users who convert well from signup to deposit, and Popunder provides the scale you need to grow volume.

06 My take

Put this issue next to issues 4 and 8:

In all three issues, impressions cost more and the paid-out step cost less.

Two details in this issue stuck with me: the signup step showed almost no difference, and the whole gap was in deposits; and the first half of the month was only 8% cheaper while the second half stretched to 26%.

Put together, the two details mean that if you test too briefly or look too shallowly, you’ll shut it off.

If you have an offer paid per deposit, you can run Paid Social and Pop together in the same country, compare them at the deposit step, and run a full cycle before drawing a conclusion.

Note: the revenue and ROI figures in this article are historical results of individuals or cases and do not represent typical results; paid advertising carries a risk of loss, so test with a small budget first.