You mean, less than two years? Google was founded in August 1998 and they they hired their first sales guy in May 1999. AdWords launched in October 2000 but be

You mean, less than two years? Google was founded in August 1998 and they they hired their first sales guy in May 1999. AdWords launched in October 2000 but before that time they had revenue from backend search deals where they powered other sites search engines for a fee, like Netscape which launched in June 1999. So it's not really the case that Google had no revenue for years. They were able to generate revenue very fast by selling their tech to other companies.