I just want to add one thing: The quality of the presentation, design, and execution is better than many Ycombinator start-ups (at launch day/ first couple of months). I haven't tried the actual product, but from outside it looks neat and well presented.

Now there are lots of pretty damn good sites that YC alumni are making from launch day; but the fact that a good number isn't, suggests that PG might want to improve his filter process a bit.