For Starters you should emphasise on the Following.

- Make 2 Versions of the Avatars - One Watermarked and other without them for $1.00 or something.

- Keep the Avatar List Updated.

- Keep the Design Attractive, but make sure your Site is fast to load. Use .GIF Where Possible. Currently I Personally think its quite DULL. Add more Icons to the Newest Editions. Kindly like a 3-Column page would look good.

Just my thoughts.