[macrael]

An important distinction between this and Google's sponsored search results in that it is happening in typeahead completion instead of on a results page. As far as I know, google does not put sponsored results in its completion suggestions (though even that is a little different: selecting a google suggestion takes you to the corresponding search page, not to where you ultimately want to go, as the facebook search does). And the real difference is that when you go to a page of google search results, even if there are sponsored results, you have to click on an ad to go there. In Facebook search, the expected result of typing someone's name into the search bar is to press enter and immediately go to their page.

I find the sponsored results in Google to be much less off putting.

[gojomo]

…google does not put sponsored results in its completion suggestions…

Not yet, at least – but if you use 'Instant', where the results are appearing below the completion dropdown, you will see ads flashing there on less-than-your-full query.