I don't know about most people, but when I want to learn about the merits of a product or company, my first thought is to search for a variety of independent opinions of it, not the product/company's own marketing.
Thus, the last thing I would want to do is go to its Facebook page. I might want to go to its website first to understand what they themselves are trying to do in their own words, but Google can do that just fine, thank you. Thus, I don't really understand what niche they're trying to fill.
Facebook's search strategy reaches outside its walled garden and stretches out to the open web. So Facebook search results might include a few Facebook pages, but the majority of results will be web-pages that were more "liked" than others.
I think where it gets interesting is when you narrow the scope down to just what your friends "liked", or what men in the South Bay "liked," or people interested in football, engineering, art, or who are doctors, etc. You start to get into the long tail of search, which might open up some very interesting results.
That's what I do too. However, there are a lot of users who simply want to buy something. There are also a lot of users who are on Facebook all the time. It almost IS the internet to them.
Thus, the last thing I would want to do is go to its Facebook page. I might want to go to its website first to understand what they themselves are trying to do in their own words, but Google can do that just fine, thank you. Thus, I don't really understand what niche they're trying to fill.