If all goes well, Facebook gets a lot of money — and time — to do what it pleases until it decides to go public. And Goldman Sachs gets a piece of a hot new company, the ability to offer special clients an exclusive investment opportunity, and the likelihood of more lucrative business with Facebook down the road.

But there are also potential downsides in Goldman’s $450 million investment in Facebook, and its $1.5 billion offering to allow clients to invest through a special purpose vehicle. There could be downsides for Facebook, for Goldman, and for the investing public.