I guess you mean for a single click? I don't have any proof like you've asked for so this is kinda a waste of a post, but I've gotten something like ~$3.50 for a single click. So it isn't AMAZING but I wouldn't say no As for the niche, it must've been an arcade/gaming site.
Never anymore I sold the site. But in the few weeks (about 3 or 4) I had it probably about 2-3 of them clicks, and my site was still in beta stage (and therefore not advertised). Dunno if the Niche still pays as good though.
Probably because the thread is about your best ppc amount. Its easy to say oh yeah I got $3.70 per click, but when you ask people to prove it often this does not happen.
Well I fail to understand why would one tell a lie about his highest AdSense PPC. What proof is required? Do you want to know the niche he / shee is using? Why do you want to know in the first place. You had to trust that is the best thing instead of asking proofs.