I read the rules about newbies posting, so I can't post any links. I'm also not a salesman, I just have Isara as my homepage and stumbled on this.
Isara uses a google search engine, yes. Do they pay for it? No. It's totally free.
Put this in your address bar and it explains Google Adsense: isaraurl.com/j6rcS
They are working on getting their own servers to sort the internet, but Google started out small so I think they might get there someday.
They use 100% of revenue to fund projects, nothing goes to pay operating expenses, that's all donated elsewhere. Might I suggest you go back to isara and read the 'about' page.
I've enjoyed their forum, use their pic storage and their url shortener. As for how they chose projects, I don't know. They've given away helmets, safety vests, school supplies, rain gear, painted ugly buildings, and taken orphans to see movies. Nothing you can really argue with.