PG: If you read through an application where nothing "jumped out", but the team had a fully functional web app to look at and the idea was interesting, would you ignore the web app?
I'm not entirely sure they look at referenced URLs. They were seemingly entirely taken by surprise that we were launched and had paying customers when we arrived in Boston for the interview and had a demo to show. (But, maybe they'd just forgotten, based on the fact that they'd seen 300-400 applications, and probably at least half as many websites.)
Which brings up the advice I've given to folks that I've talked to about getting to the interview: Demo early. We only had a couple of minutes to demo, after running through everyone's questions...and it was almost certainly only on the strength of the demo that we got the yes.
I think we knew you were launched when we read your application, but we'd archived that by the time you arrived for the interview.
One of the weird consequences of dealing with very large numbers of startups is that you really can't remember anything except essentials. When the 19 new startups showed up for the first dinner this summer, I probably could have only told you what 3 or 4 of them were doing. The rest had to remind me. (Of course, once the summer gets going, I keep them all loaded in memory all the time.)