Another idea: Since Apple knows exactly how much money I've spent in their store, that signal can somehow also be weighed in with my reviews.
This means that reviews by people that have spent a fair amount in the app store would get a better/heavier scores than those that have not yet spent as much money in the store.
This would be susceptible to the same problems as Chris mentions in his post:
> Companies like TapJoy let you pay to get in the Top 25, and then once you are there you can get “organic” downloads by being on the toplists.
If they can arrange to actually buy enough copies of an application to get into the Top 25, reviews posted by those accounts would surely weigh very highly under your proposed scheme as well.
This means that reviews by people that have spent a fair amount in the app store would get a better/heavier scores than those that have not yet spent as much money in the store.