Facebook launched a mobile advertising network at its F8 developer conference, giving it the ability to target users across the applications they use while targeting them based on the information they have shared with Facebook. Facebook Audience Network, as the new product is called, will allow brands to advertise on third-party apps using Facebook's detailed targeting data. The network, which Facebook has been testing since 2012, will let advertisers use both standard banner ads and custom units. It will compete with companies like AdMob, InMobi, and Twitter, which has taken a similar approach to mobile advertising since acquiring the ad network MoPub last year. Mobile advertising has been hugely successful for Facebook, which says it has 1 million advertisers using its platform.