Pros
Caveat: I was there before and after the acquisition of Buy.com by Rakuten. Good learning opportunity. In my time there, I was able to learn a lot about how ecommerce sites operate, including managing manufacturer and merchant partnerships. Decent perks. Company used to provide lunch everyday, and then it became twice a week (not sure what it is anymore). They would also have an In N Out truck that came out once a month, which was nice. Nice people. For the most part, people are nice and genuine.
Cons
Lack of/Bad Direction. The CEO of the parent company, HIroshi Mikitani, is busy running a global company, of which Buy.com is a very small part. He seems to determine major strategy decisions based on a couple of his "liaisons" stationed in the company. Being on the front lines, there seemed to be a disconnect between "Mickey's" decisions and the actual US Market (Yes, Mr. MIkitani actually prefers to be addressed as "Mickey") Weird culture. The company is a mix of OC culture (pretty fair on work/life balance) and Japanese culture (late hours, put in your face-time, don't leave til your boss leaves, etc). It partially depends on which group you're in. Business is tough. Buy.com doesn't have much a differentiation from Amazon (1st party business) and eBay (marketplace business), and they definitely don't do either as well as the other guys. It's a difficult market to compete in. Lots of turnover. Plenty of people moving on to greener pastures. If you stick around long enough, and have some talent/skill, you got a good chance of progressing. There's some politicking involved, but probably not more than the average company of similar size.