I wish more people would do this, but sometimes it's a tough sell. I once tried to encourage a bunch of people who were banging their heads bloody trying to contribute to Facebook's places database to switch to editing OpenStreetMap instead. Most didn't want to switch -- they were convinced that their miserable experience improving Facebook was more impactful because it was a more popular product that they knew they used.

I with OSM would come out with a consumer-focused map product. I think that would go a long way towards attracting more contributors, since most people get started to scratch an itch in a product they use.