I find this rather odd, since these numbers actually mean a lot to YCombinator. You even blogged that YCombinator would like to create 1 million jobs recently (http://blog.ycombinator.com/new-rfs-one-million-jobs). How can you know you've reached one of your goals without even tracking the stats? Even though you don't have stats on revenue, do you at least keep track of profits? This seems like quite important/crucial information.
Ps. Don't see this post as a bash - I think what you guys are doing is awesome!
Cheers,
Sam Granger