From my experience selling services and products to large companies for the past 10 years, "interest" doesn't mean much. Everyone is interested. You don't have anything until you see the signature. And I don't mean the signature on the contract. I mean the signature on the check.

I agree with you that pg's point about startup growth is not invalidated by the realities of enterprise selling. But I think te way past those realities is to change the rules of the game. The "sale" should be a low-friction agreement to do business at some cost per unit/user/GB/etc. Growth is the. The ability of the product to go viral within the account. Essentially, it becomes the same process as a consumer sale with the one additional step of getting approved to sell into that batch of consumers.

While that might seem to be a big negative against starting an enterprise business, the advantage is that you're then convincing people to spend someone else's money which is easier than convincing them to spend their own. How else could a $.99 app look, feel, perform better than a $100,000 peice of enterprise software.