To my knowledge, they peered with other registrars and hosts to manage the vending. At least, in 2008 ish they partnered almost exclusively with Apple (for their MobileMe cloud and email services issuing everyone dotME addresses) and GoDaddy. I think others had to resell somehow through them? But I could be mistaken on that detail.
Domain squatting was a very profitable scourge on the internet back before all the obvious names were brought up , but it was one of the few popular TLD's to gain any real traction with consumers until dotAI.
I very briefly held, and did nothing with, "pants.me" which I regret to this day.