Guys, I know many of us are familiar with most of the free classifieds, but here is one that you can use that is ranking very high in local searches. Hope this helps you out.
Pat, the pay per click is iffy. People will not search that website, or yellow pages, etc. They use Google, and the other search engines. Google may eventually take them there, but ultimately google is the main vehicle for roof cleaning searches. I would just maximally optimize your website and your ranking(s) will shoot up and hold if you maintain them.
Important: Alot of guys create a listing, then forget about it. Some of these listings feed off of other classifieds, helping to rank each other, so be sure not to neglect them, and make sure if they expire, to renew them.
Looking back through some old posts, I see where Tucker commented almost the exact same as me, or vice versa. Yellow Pages, Yellow Book, Superpages, Etc. will not garner much attention for local searches when our own listings show up above them.