I never subscribed, but I bought each new issue for a few months when I was 13. Back then they would display the top fan art that people sent in, and I remember drawing a picture of Mario, Peach, Toad and Yoshi on top of a mushroom platform and mailing it to them. I got a letter back saying they liked my drawing and that I should keep a sketchbook to practice. Yeah, they didn't put my picture in the magazine...
Eventually they stopped receiving/posting fan art. Too bad.