After firing CEO Carol Bartz way back in September, Yahoo!'s board has officially appointed a new chief executive: current PayPal President Scott Thompson.

Thompson, 54, has been running eBay's dominent digital payments service since 2008. At PayPal, Thompson more than doubled the company's user base (currently 104 million) and revenue (currently more than $4 billion), but he'll have a challenge in turning around Yahoo!, which is a media force and content creator as opposed to a tech outfit built on algorithms.

Yahoo!, once one of the Internet's most influential companies, has been struggling to grow its business in an online world dominated by Google, Facebook and mobile apps.

[via NYT]