Yes, it's true, one of the biggest complaints people have with parking companies is a high lack of transparency about how they work - what their acceptance criteria are, how they track, report, and share revenue, what types of names they'll actually put up with (e.g. porn, trademarks, etc.) and so on. If you're really interested in parking, it's somewhat like many of the other things we do - get into one or a few, test them out, see how they work, and learn and adapt. Once you're in and using a system, you can start to learn more about it.