Doubts of their existence aside, I still agree with the OP; ads like this make me think that I'd hate working for the founder posting them. If he wants me to try to prove my worth as a candidate, I want to know that its even worth my time to send him a portfolio/resume/cover letter.
I think we both agree this job posting is not very appealing especially considering the amount of positions currently available for developers. Most good developers I know do just as much if not more screening than the companies hiring them. I know a number of companies in need of good developers that have great working environments. I think its important for people hiring to be respectful and kind if they are serious about attracting good talent.
That said, I definitely have no faith that the graphs are real or even loosely based on reality.
It could easily be somebody else as well. 4,000,000 uniques isn't a ton of users if you're somebody like Grooveshark, Spotify, Rdio, etc.
Perhaps I have more faith in PG's judgement than I ought, but that strikes me as excessively cynical.
I'm guessing you didn't like the post (note, it's not really an 'ad' as you stated) for some reason and are coloring the entirety of their claims with the same brush.
I'm guessing that, bravado aside (and I didn't personally find anything particularly braggadocious in the post to take offense to,) I would wager real money that their claims were at least truthful.
No. Rather, I have no information that I trust to convince me one way or the other as to their honesty, so I choose to ignore that data.
I had not, however, considered that they have already been vetted by PG and YC. Perhaps I have a small reason to trust their claims. Even so, I'd give it the same weight in decision making as known hyperbole, at best. I'll only completely trust the claim if I have verifiable sources.