Google Map API wording

used only for services that are generally accessible to consumers

[BradleyT]

The API states, "The API may be used only for services that are generally accessible to consumers without charge".

If I wanted to create a service where I list locations (free) and charge the owners of that location a fee for listing a website url and a picture in the google map info window (the popup bubble) would that be OK?

In other words, the site would be free to all visitors and location owners would have the option to upgrade their listings.

Thoughts?