There are only two options here: 1) In a few years we'll be claiming this was an obvious purchase (like when Google bought YouTube) or 2) It's an obvious sign that the coming valuation of Facebook's IPO is going to people's heads and you might want to second guess your purchase of Facebook when she goes public.
Right now, the snarky in me wants to think it's #2.
I love Instagram, but 1 BILLION DOLLARS? Really?
I'd love your thoughts here …