That's assuming not-wildly-optimistic assumptions within a self-serving analysis. Dial that back to $100M rather than half a billion, and it's no longer a tremendously appealing option.

Facebook's per-user revenue for US users was $4.19 as of last October (with far smaller amounts for non-US users). And that's with years of experience, rich targeting based on multi-year social data mining, and the ability to embed several ad impressions per pageview. Is Snapchat likely to hit that high mark? Not in the short term, for sure.