I imagine if this app is integrated you can, for example, create custom user titles based on the ratings they receive. Lets say, if you have received 100 laughs you can have the title to be "i am funny", if you have 10 helpfuls the title can be "most helpful member", etc.
Take for example the iAwards application, which is integrated with Rules and can provide automatic awards based on some criteria. You can have the mentioned example to deliver awards instead of user title updates.
Another example is group promotions, for example any member with 100 heplful ratings might be moved to custom "Expert" group, etc. Really, the possibility are endless and limited only by creativity.