Google AdMob

Google AdMob is the undisputed behemoth of mobile app monetization. For the vast majority of independent developers launching their first mobile game or utility app, AdMob is the default choice because it offers an incredibly low barrier to entry and plugs directly into Google's massive global advertising network. Its primary advantage is scale. Because it taps into Google Ads, there is almost always an advertiser willing to buy ad space in an app, ensuring that developers experience very high "fill rates" (the percentage of ad requests that actually display an ad). It supports all standard ad formats, including banner ads at the bottom of the screen, full-screen interstitials between game levels, and rewarded video ads where users watch a 30-second clip in exchange for in-game currency. AdMob also functions as a powerful mediation platform. Instead of forcing developers to only use Google's ads, it allows them to integrate competing ad networks (like Unity Ads or AppLovin). The AdMob engine then acts as an auctioneer, forcing the networks to bid against each other in real-time, displaying the ad that pays the developer the highest possible amount.