This is a pure mathematics and there is a formular for it.
1,000,000 address = A
Number of transactions on address = B (this might also have an average because some account could do more transactions than others)
Bitcoin network charge per transaction = C
You can complete the rest on your own.
yes i know, already provided an average for bitcoin as a whole in yesterday's edit.
The thing is, the number of transactions would depend on the users' activity and the services you provide, so basically on the your "business expectation". Which is what i'm interested in.
Because, for example with the transaction fees average, if you can gain $30k/million/year doesn't mean you'll pay $1/10/20k for it. Given that you're the one generating all of that revenue.