The Game That Became an Ad Network

In the first years of the iPhone, two developers had a problem that sounds almost comic now: their game was popular, but popularity did not settle the bill. Lee Linden and Ben Lewis had made TapDefense, a tower defense game that would pass 20 million downloads. Players wanted to keep playing. A smaller number wanted to pay. Between those two facts lay a business.

Their answer was an exchange. A player could do something an advertiser wanted - install an app, watch a video, fill out an offer - and receive a game's virtual currency. To the player, the currency felt like a shortcut. To the advertiser, the action was measurable. To the game maker, it was revenue from someone who might otherwise never spend a dollar. The advertising service that emerged from that experiment became Tapjoy.

Three parties, one tiny bargain

Today's Tapjoy, marketed as Tapjoy from Unity, is an in-app rewarded marketplace. A publisher places the offerwall inside a mobile game or app. A player opens it voluntarily and chooses from advertiser tasks. Complete one and the player gets coins, gems, lives, or another reward set by the publisher. The advertiser pays for a completed action; the publisher shares in that advertising value. Public materials do not disclose a standard fee or publisher split.

This is why the product appeals to free-to-play games. The paywall is a blunt instrument: some players will pay, many will leave, and a great many will keep playing without buying anything. Tapjoy gives that last group a different route to premium content. For advertisers, a completed task can be more useful than an impression. Unity now offers cost-per-action, multi-reward engagement and Daily Rewards campaigns, plus publisher controls for placements, exchange rates and geographic pricing.

The difference from a standard banner or interstitial is agency. The player opens the offerwall and picks an offer. The difference from an ordinary in-app purchase is who writes the check. Yet it is not free in the everyday sense. Offers can ask for time, app use, information, a subscription or a purchase. The wording of each offer matters as much as the size of the jewel beside it.

The founders had already run the experiment

A 2012 filing describing the founders says Linden and Lewis started Tapjoy in August 2008 with TapDefense. The same account says their ads business reached $1 million a month in revenue by March 2010. That month, Offerpal Media bought Tapjoy, joining an iPhone-centered operation to an established virtual-currency network for social games. Company profiles often date the combined business to Offerpal's 2007 start; the game-born Tapjoy project came later.

That origin gave Tapjoy a useful bias. Its founders had felt the publisher's problem from the inside. The company was selling a way to make an economy work, not merely a rectangle of screen space. By July 2011, it had announced a $30 million Series D led by investors advised by J.P. Morgan Asset Management, with existing investors joining in. The cash was meant to expand technology and advertiser relationships.

Then the storekeeper changed the rules

The early model depended heavily on installs. Advertisers could pay to put their apps in front of players, who would download them in exchange for currency. It was effective enough to raise an uncomfortable question for Apple: were people installing an app because they wanted it, or because another game had paid them in gems? In 2011, Apple began rejecting some apps that used incentivized install mechanisms and changed how its charts treated them.

Tapjoy adjusted its promotion mechanics and later launched a web-based marketplace. Neither move was a grand conversion; both were practical responses to a platform owner changing the terms. The episode is a reminder that a company can own the ad relationship and still rent the doorway. App-store rules, operating-system tracking and publisher placements can all alter the economics overnight.

“Our goal is to help mobile developers improve their applications, grow their user bases and generate higher revenues.”Lee Linden, at the 2010 Offerpal transaction

The expensive part of a virtual coin

Tapjoy's most consequential product flaw was painfully literal. The Federal Trade Commission alleged that consumers completed offers and did not receive the promised in-game rewards. The complaint described hundreds of thousands of complaints and difficulties reaching support. Some offers had required people to spend money or disclose personal information. In March 2021, the FTC finalized a settlement requiring Tapjoy to stop misleading users about rewards and improve how it handles complaints.

The case exposes the weakest link in a three-sided marketplace. The advertiser sees a completed action; the publisher expects a satisfied player; the player sees only an empty wallet. Tracking breaks, offer terms are disputed, support is hard to find, and the reward's face value becomes irrelevant. A virtual diamond can carry a very real cost in time, data or cash. When it fails to arrive, the player remembers the game's name as well as Tapjoy's.

That history should temper the glossy performance charts. A publisher using an offerwall can copy the sound part of Tapjoy's idea: let users choose a reward, price the virtual currency deliberately, make offers visible at a useful moment, and measure whether revenue is incremental. The operational test is just as important. Track completions, test the reward path yourself, make disputes easy to file, and monitor unresolved complaints. The model is less persuasive in games without a meaningful in-app economy, where an outside task ruins the rhythm of play, or where rewards cannot be delivered reliably.

The market bought the bargain anyway

The FTC settlement did not end the business. In October 2021, ironSource agreed to buy Tapjoy for roughly $400 million; it closed the deal in January 2022. ironSource estimated Tapjoy would bring in about $81 million in net revenue for 2021, a forecast rather than a published final figure. Its announcement claimed an SDK footprint of about 66,000 apps and reach of more than 1.6 billion monthly active users. Unity's merger with ironSource later in 2022 made Tapjoy one product in a much larger mobile growth and monetization suite.

Aiming, the Japanese game developer, shows what that job entails. It added rewarded video and Tapjoy's offerwall to Charast Magical Academy, a title designed with ads in mind. In Unity's case study, the team said it delayed ad badges for new players after some took the markers as a requirement for progress. It also found that a currency sale plus a prominent in-game badge raised impressions far more than the sale alone. Unity reported an 80% increase in engagement rate for the project. The lesson is more interesting than the percentage: placement changes behavior, including behavior you did not intend.

More recently, Unity has added Daily Rewards, where advertisers can reward successive milestones rather than a single install, and a rebuilt publisher dashboard with placement reporting and A/B tests. Those changes suggest a shift toward managing an ongoing in-game economy, with measurement after the click. A game publisher can test currency exchange rates by country or offer position; an advertiser can bid for deeper engagement instead of buying a download and hoping it lasts.

Tapjoy sits between two kinds of spending: a player's money and an advertiser's budget. Its cleverness was to let one substitute for the other, at least for a moment. Its warning is equally transferable. An exchange built on a reward is only as good as the instant the reward appears. Everything before that is a promise.