And Square's valued at 3 times that. Yet this story is all about how the actual performance is rougher. So I ask again, how do we know Stripe is actually crushing it? (Also why does a question like that get down voted?)

http://techcrunch.com/2014/01/13/putting-squares-5b-valuatio...

Also, Stripe's "$1.75 billion" valuation is misleading because the round was for preferred shares, which have privileges (and lower risk than common stock). We saw something similar for AirBnb, which Marc Andreessen pointed out in a series of tweets:

https://twitter.com/pmarca/status/457017580385873921

Square's valuation was based on common stock.

Valuations do not mean you are "crushing it", or that "crushing it" will mean anything in three month's time. Take a look at Zynga for an example.

Eh, these are people that had a look at Stripe's financials and decided to invest in it at that valuation. I'm not going to speculate on their actual numbers, but I trust that Sequoia and co have a good idea what they're doing.