Microsoft revealed plans to revamp its Web search and ad search businesses with a new search service in partnership with Facebook.

Microsoft Senior President Satya Nadella revealed during the company’s annual meeting for financial analysis that the partnership will cover only U.S. Facebook users, WSJ reports. It still remains unclear whether the rest of the social networking site’s users will benefit from it in the future.

The Redmond-based company promised to bring Web search service and advertisements to Facebook users by the end of the year, in an attempt to catch up with Google, who continues to maintain a leader position in the search business.

“We need more relevant ads,” said Ballmer during his keynote at the financial meeting, highlighting that one of the advantages that the current market leader has is that they have more advertisers in their system, which means “they have more opportunity to serve up a relevant ad.”

Microsoft is currently looking for a quick and simple way to expand their audience, especially following the failed attempts to close the acquisition deal with Yahoo this year.

“Search is interesting, it's not content, it's not community, and it's not commerce, but search is an important part, it's sort of a killer app, if you will, for this new world,” said Ballmer. “It's a starting point to the world in which everything has moved to be digital.”

The deal with Facebook will be like a two way street: it will expand Microsoft’s audience with some 30 million U.S. users, and it will help Facebook users with their search queries without ever having to leave the social networking site.

This spring, Microsoft rolled out a method that literally pays users for using their search engine when purchasing something online. The service is called Microsoft Live Cashback, and Microsoft is very excited about it, as “it delivers value to both end users and advertisers,” as Nadella said.