Yahoo! has appointed Scott Thompson, former president of the eBay-owned online payment services company PayPal, its new CEO.

The appointment, announced Wednesday, came about four months after Yahoo!’s board of directors fired the previous CEO Carol Bartz and installed CFO Tim Morse to run the internet giant in the interim. Morse will return to performing CFO duties for the company whose current user count is about 700m.

Roy Bostock, chairman of the Yahoo! board, said Thompson’s record of successfully using a company’s existing assets to “reignite innovation and drive growth” was exactly what Yahoo! needed.

“His deep understanding of online businesses combined with his team-building and operational capabilities will restore the energy, focus, and momentum necessary to grow the core business and deliver increased value for our shareholders,” Bostock said.

Thompson said in addition to focusing on getting to know his new team, his immediate concern will be to get an understanding of the needs of the company’s advertisers and publishers.

“Clearly, speed is important but we will attack both the opportunity ahead and the competitive challenges with an appropriate balance of urgency and thoughtfulness. I cannot wait to get started,” he said.

Before he became PayPal’s president, Thompson served as its SVP and CTO. He came to PayPal from Inovant, a Visa subsidiary that oversees the company’s global technology. Thompson served as the executive VP at Inovant.

His record also includes a stint as CIO at Barclay’s Global Investors and work at Coopers and Lybrand (now PricewaterhouseCoopers).

In addition to being an internet heavyweight, Yahoo! has had one of the most innovative approaches to data center infrastructure. In 2010, the company launched the first data center built to its own reportedly extremely energy efficient “computing coop” design in Lockport, New York.

The company has since started projects to build coop data centers in other locations around the world.