Why one investor believes Pinterest is worth $2.5 billion

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When Facebook tanked in its initial public offering, the social network eroded the perceived value of private consumer Internet companies -- save for Pinterest. Despite a lack of revenue, the scrapbooking site is now worth an unfathomable $2.5 billion.

Making an educated guess at best, investors like Rick Heitzmann, founder and managing director of FirstMark Capital, have pinned their pocketbooks to a service that merely offers the promise of future reward. FirstMark Capital was Pinterest's first institutional investor. The firm has participated in every one of the startup's funding rounds, including the monster $100 million round announced yesterday.

"Pinterest is a company whose product has really hit a core consumer use case," Heitzmann told CNET. "It's one of the fastest growing sites in the history of the Internet."

That use case, said Heitzmann, is discovery -- or a way to start your online quest for a new backpack, first-date dress, or vegan meal to cook for dinner.

Heitzmann is, at the very least, right about one th... [Read more]