You're thinking in the wrong terms. Is the Instagram brand worth less than 1% of Facebook? Also, I see hordes of high school and college females- especially the 'popular' ones with iphones- using instagram. When you have possibly the best target market, and a tiny valuation for what basically is facebook's other lifeblood (photos are second only to the social graph), Instagram was positively cheap.

I'm sorry, I think we're living on different planets.

Edit: I don't mean to rubbish what you're saying. I agree that it and the brand have value but to me that equates to something like $150 to maybe $250 million at a push. $1 billion is off the wall.

Edit 2: as is a $100 billion valuation for FB.

Facebook isn't worth $100 billion, considering that last year's revenue was only $3.7 billion.