They must be investing in some enormous infrastructure. Server farms, international markets, maybe Akamai. But in general, it's not uncommon for companies that

They must be investing in some enormous infrastructure. Server farms, international markets, maybe Akamai. But in general, it's not uncommon for companies that raise a lot of capital for rapid growth to not be profitable. Back in AOL's heyday, they had huge revenue growth, but they were reinvesting it in customer acquisition so fast that they never started to make money until their growth slowed down. This also happened in the retail boom in the 80s with companies like Home Depot and Staples. They kept building out more stores, which cost them more money than they were making. Having said all that, I really fail to understand valuing Ning at half a billion dollars. It seems like a useful thing, but only an incremental improvement over, say, Yahoo Groups.