We have a prediction market platform, but we also end up consulting most of the time as part of the implementation. As you might imagine, prediction markets can be quite disruptive. They tend to make information radically more transparent and we learned the hard way that in order to not just churn through a bunch of companies, we needed to help companies deal with 1) what key questions to ask, and 2) what are they going to do with the new signals they have? How will they incorporate them in to their decision making processes and how will they acknowledge that the "crowd" has been heard?
The average project size we work with tends to be in the low hundreds of participants, with the biggest one being in the mid-thousands.