Yeah, they did the same thing for me several months ago. I bought the original membership because I was getting a washer and dryer and I more than made up the $9.99 on that initial purchase. Later in the year I bought a Gamecube, a digital camera, and a $600 LCD monitor (the last for work - reimbursed, but the rewards are mine to keep!). But after a year I stopped going there for anything major and only bought the occasional cheap game. I had no intention of renewing. I think they offered 1/2 off and I ignored it. So then they just up and renewed it. Very strange. Maybe it has something to do with the amount you purchased in the year? I probably had $3000-$4000 with all my work expenses included. We'll see if they do it later this year when I have almost nothing spent (though I did get my PSP there).
However, I don't seem to get any of the special coupons that some people report getting for video games. Maybe that's because I only buy $10 ones...