No, this isn't an advertisement, actually I just heard about this site last night. You can make your own ringtones that get sent to your phone for free, no subscription, and no money transferring hands at all. It's all ad supported. I just chose to send a ringtone to my phone, waiting for the text message to arrive.
http://www.phonezoo.com
Sorry if it's old news, just thought it was cool, and now you don't have to spend money to get ringtones. I read the Terms of Service and Privacy Policy, it all looks legit, they don't sell your name or number out and they don't send you advertisements to your phone or anything. Even though they seem legit I'd still say use at your own risk, but so far nothing has happened to me or the kid who showed me the site.