Many SaaS development teams have enough data about usage to see that "a very large percentage of our ideas are bad." The challenge is actually using the data to drive a move away from vague product strategies, to directly seeing what customers care about. They have "Lean Startup" on their minds. They hunger to deliver work that has significance and meaning. I had at least a dozen conversations about this topic in the last month. It's the next frontier for all product development.
Here is the guide that I wrote for my team. Please feel free to use it, modify it, and improve it. Our internal version listed pecific examples of time that we wasted, which have been removed to protect the guilty, which was often me.