Consider Facebook, the popular but financially unproven social networking site, which is reportedly being valued by investors at up to $15 billion. That is nearly half the value of Yahoo, a company with 38 times as many employees and, based on estimates of Facebook's income, 32 times more revenue. Google, which recently surged past $600 a share, is now worth more than IBM, a company with eight times more revenue.

More broadly, Internet start-ups are drawing investment based on their ability to build an audience, not bring in revenue - the very alchemy that many say led to the inflating and undoing of the dot-com bubble.

The surge in the perceived value of some start-ups has even surprised some entrepreneurs who are benefiting from it. A year ago, Yahoo invested in Right Media, a New York company developing an online advertising network. Yahoo's investment valued the company at $200 million. Six months later, when Yahoo acquired Right Media outright, the purchase price had swelled to $850 million.

Get the full story at the International Herald Tribune