Microsoft and Yahoo signed their 10-year search deal in mid-2009 and got regulatory clearance for it in early 2010. However, for a variety of reasons both technical and operational, the partnership hasn't yielded the expected results.

When the deal was struck, Yahoo and Microsoft believed it would allow them to better compete against Google, which dominates search usage and advertising, but Google has maintained its position.

At a general level, the deal puts Microsoft in charge of Web crawling, indexing and ranking, and of self-serve, pay-per-click ad sales. Yahoo, on the other hand, agreed to pay Microsoft a commission for paid clicks on its own sites and partner sites, and to be in charge of selling premium, guaranteed search ads for both companies.

When the deal was signed, Yahoo estimated that, when fully implemented, the arrangement would boost its annual operating income by about $500 million, provide capital expenditure savings of about $200 million and increase annual operating cash flow by about $275 million.

Mayer also said she's committed to Yahoo's content business -- both to its user-generated sites, such as Yahoo Answers, and to its professional content sites, which feature videos, photos and articles from partner media companies and Yahoo journalists. Improving personalization of content and ads is key for Yahoo, she said.