All investors then were just overly cautious? Or perhaps there are now others ways to make money off of a company, not tied to the companies actual success and the value it adds to the economy?
Actually, MongoDB (formerly 10gen) is 6 years old. After 6 years, Salesforce's market cap was around $3 billion. (They IPO'd after 5 years.)
Salesforce revenue in the year of their IPO: $96M. IPO: $110M
MongoDB revenue last year: $36M [1]
[1] http://wikibon.org/wiki/v/Big_Data_Vendor_Revenue_and_Market...
One counterpoint. My friend worked at a university. This was back in the era of punch-cards. Oracle came in with their relational database sales pitch (they were basically a very small sales team). His manager (who managed the punch-carders) saw the huge potential that everyone else did not (e.g. 'never going to happen'). Bought Oracle stock right when it went public (mid-80s). Kept on buying it. Retired in her mid 40s. Now lives on her own farm, tending her own sheep (not sure if it was sheep or some other livestock), in the country.