I don't understand how so many are constantly getting this wrong. The Web 2.0 disaster wasn't fueled by browser wars nor by some corporate acquisitions. Those are red herrings. I was someone working inside a university IT department at the time. Other than torrenting, the majority of Web traffic was to Facebook.com The root cause of Web 2.0 growth is Facebook branching out from university into the general public. If you're frantically searching for a second driver, you can add the explosion of iPhone sales on top of this. That's it. Anything else is a minor feedback loop that was attempting to latch onto the rocket growth levels of new Facebook users.
That might be but the odd coincidence of being precisely where you think the most important thing happened is probably a good reason to closely check this theory against the usual laundry list of potential biases.
You can dismiss this as bias, however I'm a firsthand witness to it. The growth was true in every single university I emailed about the problem. Facebook's user growth was absolutely wild and unprecedented from 2007-2010. In fact, here's a graph showing an exponential curve.
I'm not dismissing it, just saying that 'being a witness' can very much be a cornerstone of bias. The people working at maternity wards who notice more births at full moons are very much real witnesses to real events, for instance.