As someone who's completed the campaign, I'm finding that there's not a huge motivation to replay old adventures. The quests are kind of cool, but (for me anyway) aren't as productive as just playing mp. My suggestion is to have some sort of featured adventure on a regular basis (daily or weekly). Either a regular adventure with better rewards (perhaps made more challenging), or a community made adventure (if we ever get the ability to make our own). If the pizza-required adventures were part of the rotation, that would also be another motivator to unlock those... Just some food for thought.
I don't really feel that its needed but if so definitely a player made map with just regular adventure reward. Based on some kind of voting or contest would be awesome.
