Experiment: How tap4fun reached gamers most likely to play and pay with automated bidding

December 2020

What we set out to test

Can app marketers unlock more return on ad spend (ROAS) by optimizing their automated bidding strategy?

The background

Founded in 2008, tap4fun is a game development company headquartered in Chengdu, China. One of its newer mobile games, Kiss of War, has already been downloaded more than 1 million times since launching in September 2019. The brand traditionally used target cost-per-action (tCPA) bidding to connect prospective players with all of its games, and it had been promoting Kiss of War with the same strategy for more than a year.

Although tap4fun had seen success with tCPA bidding, it noticed a decreasing ROAS while monitoring its day-to-day campaign performance. Eager to find a better way of reaching more players who were likely to make an in-app purchase, tap4fun decided to elevate its existing App campaigns with target ROAS (tROAS) bidding.

How we set the experiment up

One of tap4fun’s goals was finding a way to increase its marketing investment across Europe while meeting its ROAS target. So, the brand started its first tests with tROAS bidding in the United Kingdom, France, and Germany. With its creative featuring Kiss of War’s range of characters ready to go, tap4fun set up a traffic split test with Google’s global product engineering team to gauge the impact of tROAS bidding across iOS devices:

  • Control group: Served App ads with tCPA bidding optimized for in-app purchases
  • Test group: Served App ads with tROAS bidding geared toward a ROAS goal
The brand’s ads enticed people to play Kiss of War by sharing snippets of in-game experiences.

After running its test for six weeks throughout March and April 2020, tap4fun compared the two bidding strategies by assessing how many people downloaded Kiss of War within seven days of watching its App ads.

What we learned

Game and app developers can connect with their most valuable users and consequently increase ROAS with a value-based automated bidding strategy. Within the six-week test period, tap4fun found that tROAS bidding drove 80% more ROAS than tCPA bidding with comparable budgets.


Since its experiment, tap4fun has established tROAS bidding as a best practice for all new game launches and has implemented this strategy across all of Kiss of War’s marketing campaigns. The brand also plans to increase its investment in campaigns using tROAS bidding in the United States and Asia.

“We found a new opportunity to connect with our most valuable, engaged gamers by switching to a bidding strategy best suited to our goals. Now that we’ve uncovered a better way to reach prospective users, we feel even more confident in expanding our investment across other markets.” — Ricky Song, Vice President, tap4fun

This case study is part of the Experiment with Google Ads program.

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