As the mobile app economy grows, app developers have been willing to pay increasing amounts to advertise on major sites like Facebook to boost their app downloads.

Twitter said Thursday it could reach 1 billion unique mobile devices through its MoPub network, which places ads inside of hundreds of apps. Twitter, which acquired MoPub last year for roughly USD 350 million, reaches a more limited audience of 240 million users through its own Twitter.com Web site and mobile apps.

Twitter said it would allow developers to target their so-called app-install ads on Twitter, based on user interests. For example, a game publisher could promote its mobile games to Twitter users who have been identified as gamers.

Facebook Inc chief executive Mark Zuckerberg has in the past repeatedly identified app-install ads as a significant source of revenue for the world's No 1 social network, although Facebook has never disclosed the precise amount in its financial results.

(Agencies)