There seems to be some mechanism where the free trial period expires, and you must pay after that point.

I have been using the service for three months now, and can still access routes and map data. I haven't done a ton of routes, so my guess is they may turn off the trial once you've downloaded a certain number of routes.

I also believe they tie your PIN to the trial, so uninstalling/reinstalling the software would not reset your trial period.