This gets difficult as more employees join. Typically companies set aside a portion initially, and then keep splitting that portion.

There are consumer-owner / member-owned co-ops where the people that purchase the service (say in a yearly subscription) end up as owners.

The purchase price usually doesn't get you ownership though, you buy shares (or whatever their equivalent name is) to become a member, which then entitles you to buy the services they offer.

How many people do you expect to join? Are you trying to solve a problem you'll never have? Even if you run out of shares you can always dilute your existing shares to add more people.