Okay, sometimes I do use it to link back to my site but that's usually just when someone new finds my blog (and leaves a comment). If they took the time to leave me a comment then we must have something in common. So I check out their blog and say something to the effect of "Thanks for stopping by my blog. Hope to see you again!"
Alyssa at Keeping the Kingdom First asked "How on earth did you leave a link in your comment on my blog? Do tell!!"
Because you asked, Alyssa, here you go! Figured I might as well post it in case anyone else was curious.