Microsoft completely dominating the PC software industry for nearly 30 years, reaping insane profits for that entire time. In some ways they still do dominate it, certainly in terms of productivity software and business email.
Similarly, IBM was computers for 30 years.
Comparing them to simply the most popular social website for the past 10 years is not really fair. The fact that Facebooks value approaches those other two companies only shows how insane the current bubble is.
