Facebook already has a "search engine" in their search box. You say no one uses it because it's not good (not sure that's true), I say no one uses it because Facebook is not the place where people search for things on the internet.
Remember that Microsoft made it very convenient to use MSN Search for many years by setting it to the default home page and having it in their search box of IE. It didn't work, people typed google.com and did their searches there.
And you're wrong about advertising. Facebook's is valuable but it will never be as valuable as that of people who are searching for something with the intent of buying that thing.
Remember that Microsoft made it very convenient to use MSN Search for many years by setting it to the default home page and having it in their search box of IE. It didn't work, people typed google.com and did their searches there.
And you're wrong about advertising. Facebook's is valuable but it will never be as valuable as that of people who are searching for something with the intent of buying that thing.