Penetration rate

This is a measure or an estimate of the amount, or
rather, percentage of the amount of people in the population density
that will utilize a particular service. In the instance of the 100,000
possible users, only 5 percent may want a particular service. Therefore,
the possible usage may only be experienced by 5,000 people for that
service offering. An important issue is that each service offering will
likely have a different penetration and that it is very possible that
based on the amount of services offered the total penetration rate could
exceed 100 percent because of the various service offerings.