Google has announced they are purchasing AdMob Inc, which is a developer tech that places adverts into thousands of mobile phone app, and is paying $750 million in Google stock reports the LA Times.

The acquisition of AdMob is one of Google,s largest purchases and shows their “double-barrelled” strategy for attracting consumers with free tools and then charging advertises to advertise to their massive audience.

Virtually all of Google’s annual revenue of $22 billion is generated via advertising, and Google continues to add more and more free services and apps to draw a larger audience which is valuable to advertisers.