GeoIP information

How do service providers get all the GeoIP companies to have correct information for their address ranges? Do they just pay them to update it? At first I thought it had to do with whois data, but my home Verizon IP whois lists Ashburn, VA, yet the GeoIP data shows my local city. We're trying to find a way to correct our GeoIP data for a specific IP range, but aren't sure what the best practices are for doing so. Any advice would be awesome! -- Ian Clark Network Engineer DreamHost