Google started enabling a vote system based on 1-5 rates for Videos on Youtube. They noticed people were using it as a mere Boolean switch: 1 or 5.

You may use a Star system, but expect rather unbalanced results where most of the feedback will come in the shape of 1(noup) - 5(liike). You may want to skip the experiment and rather design a simple 'yay/nay' approach.

Relevante Link

[youtube comes to a 5 star realization its ratings are useless][1]