A pilot is more or less a working version of the end solution that is deployed for Production use to a small set of users. A successful pilot is a very strong indication (almost certain) that the designed workflow solution will work well in a Production setting.
We are comfortable with free pilots because in most cases a production-ready ZMDM based workflow solution will be ready in a few weeks. We are pretty confident that by the end of the free pilot you and your team will love ZMDM.