I will begin with a statement of fact. @NetFlix, if you do not know, has a five star rating system. So you as a viewer are sitting there at the end of a movie wondering if you can give four stars something you just watched when a few months ago you gave four stars to Platoon. You cannot give it a 3.5, just 1,2,3,4,5.
However when the starred ratings (which are shown to you as suggestions as to what you might like), viola @NetFlix displays half stars. You cannot give something one point 5 stars, but they can based on their algorithm. Based on that information, then @NetFlix is in fact working on a 1-10 rating scale.
This is not a hard concept to comprehend. If they can give 1/2 stars to something then you are by default adding the ability to have 5 more levels to for their use. That same ability is not yours, just theirs.
Here is a suggestion. @NetFlix change things to a simple 1-10 rating system. Update your algorithm. Anything under a .5 gets rounded down and anything above gets rounded up. Give your users more ability to honestly rank the things they are watching.