I think that every company that alows it's support not to reply to a urgent help request from a customer for over a week, is in big problems. I wrote two emails asking for some clarification regarding ad formats and they just ignored it. Does that suck? Yeah, you bet it does.. I am ditching them for good..
Just wait until you buy ONE fixed ad, and come in the next morning to find that their cart automatically dropped about 20 off-topic PPC sites on to your account! That after taking almost an hour to do the one ad because yes, their site was unbelievably slow. Their customer service line will be busy come 9am! I noticed their TOS states that you are not to complain about their service anywhere but to Adbrite. What are you gonna do, ban me? Oh, the humanity!
Adbrite can be pretty useful when all is working well. When I called about the PPC sites added to my cart, they answered the phone quickly and the guy was helpful and deleted all the unwanted ads. Another person from Adbrite called later in the day but I was out. So, whereas I have twice had problems with unintended billings, to their credit the customer service has been effective, proactive, and friendly.