Sounds like a cool idea. I would certainly use that.
One question on legality and its just question.
For example
If someone posts something about how amazing Disney Land is and over time it gets more votes and reaches thousands of dollar and then suddenly many Disney post appear making thousands of dollars talking about how great it is. Would Disney have the rights to that money because it was using Disney pics or logos.
Same for any product really.
Would that count?
As long as you are not using any intellectual property in your review, which you didn't have permission to use (i.e. images/video's owned by Disney), they would have no legal right to rewards generated by users opinions on how good/bad their products are.
It's would essentially be free advertising for Disney, so I would bet that they wouldn't go after anyone who even used their IP... But they would have a legal right in that case, IF they can identify the persons doing so...