There is one very special group of potential participants: Those that are hyper-implicated. They come to everything, are hyper networked, and this is just one of many things they are involved in. It is easy to rest on their participation but there are a ton of risks with this group.
Caveat 1: You are not solving their problem!
They have it already figured it out, they know ways of getting their voice heard. They won’t have big aha-moments as they participate in your thing.
These are prospects who have already solved their problem. Now, they are only sampling “the market” further, to see whether sth else tastes good.
They might show up in the beginning, but here you are in direct competion, and the other citizen iniatives might very well “taste better” and they will stop coming again/ only show up to the moments where it seem like they will have the greatest impact.