Lets have three buttons with the following meanings: I enjoyed this, This was valuable, thank you and Worthless. The buttons would apply different weights on voting: 20%, 100% and -100% respectively.

I like this idea! Perhaps with some open discussion we can come to a perfect solution, but right off the bat that's an excellent start. I have nothing to offer at the moment because my brain is overloaded. I need to go outside and inhale some pollen to set me straight again.