I think it's a mixed bag. Real life example, my mom is flying in today for a visit, she emailed me the flight info. Close to the time of departure my android phone that's link to my google account gave me a push notification about it's status which it regularly updates in case there is any delay. Is this a little creepy? To me, yes. Is it also useful? Yep.

This. I'm not sure if the other user means better experience with the services Google et al. offers or if he directly means how Google/Facebook/etc. cater ads/search results/friend suggestions to your web behavior. If it is the latter, then I personally want none of it and I get creeped out in much the same way as meeting a stranger who knows a little too much about me.