Mysterious public service ads from Adsense.

As soon as I started to talk about my secret weapon, I noticed I started to get more and more public service ads. I even tried to do some small scale keyword staffing and made sure every paragraph on my blog has the word Adsense mentioned at least once. No luck though so far. Every impression of my homepage now has public service ads, and only public service ads.

This is really puzzling. If I go to individual pages, everything seems to be OK, and I see normal Adsense ads. Homepage serves public ones. Is it Blogger feature? It's affiliation with Google makes me consider this possibility at least. Conspiracy theories aside, I'll wait a day to see if things improve after keyword staffing, and if they don't I have to come up with something else...