I'm watching this one closely. As a STH, my biggest complaint is that when I post the tickets for sale on the resale site, they add a 21.5% fee. That's only on resale tickets, of course. If you buy directly from the Celtics, there is only a $5 fee, which doesn't even show up until the end of the transaction. I don't begrudge the Celtics a profit, but man, 21.5% is a tough nut to swallow.
Here's where it gets interesting, though: I was told that I could sell tickets on third party channels, but that I would be responsible if the person who bought my tickets got into trouble, was thrown out, etc. It could put my tickets at risk. If I sell on the official resale site, however, I had no such responsibility. My rep was very, shall we say, "encouraging" to sell on the official site.
Mike