What's funny about your comment is that yellow pages uses google search and maps to compile it's results. Why not skip the cruft and go right to the original source?
yp.com has a ton of listings directly submitted to them. They may use Google as one of many data sources, but they're by no means the original source.
If you buy a print ad, you can get a cut on the .com ad and placement depending on how much you're spending. I also noticed yp.com has the first 8-10 listings are paid ads, which go right below the fold. If you don't scroll down, you'd never notice the non-paid listings.
It's pretty sketchy to me, but I guess they're doing what they have to in order to survive
> Why not skip the cruft and go right to the original source?
That depends on whether the compiling that you're skipping provides value. Why skip the gas station cruft and refine your own crude oil to make gasoline? Hey, no road tax!