I think you could be onto something with the concept of personalized banners. I’m thinking of taking it one step further by making them dynamic and programmatically generated.

This art is really cool. What if it rotated weekly?What if the banner integrated others parts of the users profile into the design, displayed stats, somehow translated the tone of the users notes into the vibe of the banner….

While technically this could be scripted pretty easily, it would all depend on creativity and great design. Done right it would be worth charging a small monthly subscription fee and as a bonus it would market itself.