[1] http://i.imgur.com/HyeKf.gif [2] http://www.internetworldstats.com/emarketing.htm
[1] http://i.imgur.com/HyeKf.gif [2] http://www.internetworldstats.com/emarketing.htm
Correlation != causation. Might as well graph it against the number of World Cup or Euro championships in that year and get a much higher correlation since the IPOs seem to all be in an even year.
It'd be much more interesting to look at perfomance vs sector and performance vs the index.
That's because Apple's and Microsoft's products don't (or didn't at the time the companies went public) rely solely on the internet. A big reason why Facebook has such a massive valuation is precisely because the population of the internet has increased so strongly.
That is one of the big differences between the dot.com bubble and today's valuations. In the 90's there were tons of people who only used their computers at work and didn't have one at home. That has flipped where lots have them at home and a large fraction have them in their pocket. So the valuation of a company that requires network access to be successful has to be proportionate to the network population.