Price mostly.

Their house brands are absolutely horrible AND expensive.

Since I've never bought from them, I have no first hand experience with their Customer Service (or severe LACK of it) but I've seen and heard way too many horror stories from people in this regard to ever want to deal with them.

Oh, and once you get in their "system" they will harrass you forever. Just ask a loyal cutomer like Scroto Thompsons calls him constantly and floods his email with garbage on almost a daily basis. I remember seeing Scotty whining about this a while back. LMFAO, his fault for ever ordering from those dopes in the first place.