If I could comment on their post (http://news.ycombinator.com/item?id=2289425), I would question the "growing 10% per day" claim. I doubt any YC funded company is going to reach 1 billion dollar worth by the end of the year.
i don't see your point with 10% & 1 billion dollar. The purpose of the 10% is to make the claim that even though it's only a soft launch, the startup is still growing, i mean if you had 10 users today, and 11 tomorrow, that's 10%. But with that kind of compounding, it can grow quick.
However windsurfer, i don't understand why you're bringing out 1 billion dollar, no one is saying they will be a billion dollar by end of the year..
There is no reference on the post about being worth $1 Billion. I don't know where you have got that idea from although, the 10% grow per day is reasonable especially considering they have soft launched. They could have 100 users and are adding 10 users per day (10%)
However windsurfer, i don't understand why you're bringing out 1 billion dollar, no one is saying they will be a billion dollar by end of the year..