Pros
I learned a ton during my time at Usablenet. I joined the company right when mobile started heating up and we were closing a new deal with a top brand everyday it seemed. The good times rolled for a few years after that and I gained experience wearing a bunch of different hats, working with huge clients and learning heaps about mobile. Made a lot of good friends and some good money there.
Cons
Too much of a a sales culture. The focus always seemed to be on the here and now and bringing in revenue that month. Everything else (product, people development, etc.) took a back seat. The development team being headquartered in Italy also never made sense. Why Usablenet never took outside funding is beyond me. The company was profitable but if we installed an experienced board and took some outside capital who knows what the firm could have ultimately become. You also ticked off a lot of client's by threatening to charge them a $.01 per page overage fee when renewal time came.