HN by itself is not a money-making product. Quora is.
Quora is not a money-making product, it wants to be one. In their present incarnations, if they just inserted ads (just for argument sake), it is not clear that Quora would make more money than HN.
You can be a profitable company by just focusing on user engagement, and not on user growth. Quora's problem is that they raised too much money and now have to give their investors a return on their investment.
I probably should have been a bit more clear about what I meant. I meant that HN's purpose isn't to directly generate revenue for YC. Quora, on the other hand, is supposed to be a product that makes money.
Quora is not a money-making product, it wants to be one. In their present incarnations, if they just inserted ads (just for argument sake), it is not clear that Quora would make more money than HN.
You can be a profitable company by just focusing on user engagement, and not on user growth. Quora's problem is that they raised too much money and now have to give their investors a return on their investment.