I'm searching for the white pages data per state. If they can deliver a white pages book to my doorstep with all this data for free, then why can't I find it online? And if there is a way, how can I get it? This is for a nonprofit market research company.

They have a website: The Official WhitePages (http://www.whitepages.com/)

Public libraries offer the Haines Criss-Cross Directory in print. Haines also features this --

Criss Cross Directory | Haines Directory - Criss-Cross.com (http://www.criss-cross.com/)

Full database of state residents (census) and white pages are not going to be the same by quite a bit. A lot of people no longer have a landline.