Donated!
For anyone wondering about the value MTo offers, let me just say that I am also a member of another great forum called All About Pocket Knives. It's a great place, very warm and welcoming just like MTo, and full of super-knowledgeable members happy to share their arcane knowledge.
BUT, if you want to send more than 100 PM's a year, or if you want to list knives for sale on the Sales Corner AT ALL, or if you want to link to an external site (like I sometimes do here with my own blog), you have to buy a membership. The rates are cheap ($20, $30, or $40 a year depending on exactly what level of use you need), but the point is MTo does all this for free because people donate.