When it came time for Goldman to allocate Facebook shares to its clients overseas, the investment bank saw so much demand it was often unable to give people the amount they requested, said one of the people familiar with the matter.

WSJ: Facebook Raises $1 Billion From Goldman Clients

In a traditional IPO, investment banks seek expressions of interest from investors, use guesswork to gauge the best price, then allocate the shares to whom they see fit.

FORBES: A Better, More Honest IPO