Yes. When I worked at Google, people were very aware that their market position is not a given and could change any time - eg as people are far less locked in t

Yes. When I worked at Google, people were very aware that their market position is not a given and could change any time - eg as people are far less locked in to Google than they used to be to Microsoft in the 1990s. Eric Schmidt used to point to an article from the late 1990s saying "the search wars are over - Yahoo won"... It wouldn't be easy obviously, but it is conceivable that someone comes up with something that is significantly better than Google/ FB, causing people to switch.