I'm not sure, but I think paying interest might raise some legal issues in terms of becoming more of a "financial institution" and such. I guess they figure most people just use it to move money in, out and around and don't use it as a bank account, per se. I don't really mind not getting interest. I mean, even if you have a 5K average balance, at 1.6% APR, which is rather high, it would net just 80 bucks per year. Whoopdeedoo.