This past weekend I drove to Kentucky, and noticed that not a whole lot of businesses showed up as POIs, even as I was passing them on the road. Here in NJ, nearly everything, but not all potential POI's in my neighborhood is listed.

How does a business/restaurant/whatever get listed as a POI? My only theory is that some places did not want to spend money to be listed as such.

well I have a small business myself and my f shows my business correctly.

and I have not paid or contacted to be on the database.

so i guess they use phone book data.

It's in canada though..

This is usually done by a specialized data provider, and depending on which one they used, how much they paid, etc., the data may not be 100% accurate (well, it never is 100% but some re better than others),