That was a good read, thanks for sharing.
I'm on the fence on this one since I've mixed views on the social media era of the net. It was great, until we switched from usernames to users (Facebook charging ahead, Google following soon after).
Controversial, but I don't mind the odd clearly marked advert targeted towards the person my browser says I am (i.e. a gamer looking for games, not someone who should be getting life insurance!) - if it isn't invasive and is showing me something I want I'll probably click it and take a look.
What we've seen evolving alongside social media is malvertising by another name - adverts that are using your desire to skip them to trick you into triggering a click. Cable-levels of advertising when listening to music - my radio offers less ads and better music sometimes. Last time I clicked an ad at work by mistake (playing a video for the class), it set of the antivirus.
The prevelance of linking online presence to your "real life", and tying in adverts to that? That's what killed it for me, and likely killed it for everyone else too. Bring back the days of MySpace and Geocities, and those plain banner ads that harmed no-one!