AdMob Explained Simply — How Free Apps Actually Make Money

Ever wonder how an app that costs nothing to download still makes money? A lot of the time, the answer is AdMob quietly working in the background.

What It Actually Does

AdMob connects app developers to advertisers who want to show ads inside mobile apps. When you see a banner ad, a full-screen ad between levels of a game, or a "watch this ad to get a reward" prompt, there's a good chance AdMob is the system deciding which ad to show and paying the developer a small amount every time. It also checks multiple ad providers at once to find whichever one pays the most for that particular ad slot, so developers earn as much as possible.

What You Can Actually Do With It

• Add different types of ads to a mobile app — banners, full-screen, or reward-based
• Automatically choose the highest-paying ad from multiple ad networks
• Track exactly how much revenue each ad placement is generating
• Control how often and where ads appear inside the app
• Combine it with in-app purchases as another way to earn from the same app

Who Is This For?

App developers who want to release a free app but still earn money from it. It's specifically for the business side of running an app — regular users won't ever open AdMob themselves, but they'll definitely see the ads it manages.

How to Start Using It

1. Go to admob.google.com
2. Sign in with your Google account
3. Register your app and choose which ad formats to include
4. Add the provided ad code into your app and publish

A Simple Way to Think About It

Think of it as the system quietly running the classified ads section of an app, automatically finding the best-paying advertiser for every available slot.

Want to see more Google tools for business and advertising? Browse the full Google Universe directory, or read our simple guide to Marketing Platform next.