Easy, we have a special agreement with an international operator that provides the Sim with a huge amount of data included and we don’t have to pay any monthly fee. We pay at once, that’s why Trackting works with no monthly fees.
The trick is that Trackting doesn’t track you while you drive, it sends just few data (parking positions only). It sends tracking data only when in Alarm mode, but this never happens (hopefully!).
NOTE: you can’t keep it voluntarily in Alarm mode (leaving the Tag at home) since this is a not authorized use.