It looks like the writer of the question might have been talking about how do you sell a game in general.

1. Build own store:

You could setup a website and process transactions yourself which is around 5-7% of the price going to banking transactions

2: Use other services:

I'm assuming it is a PC game cause you should have an idea of who to talk to if you made a game for a console. You can use gog.com or store.steampowered.com.

Most selling service stores will take 20-30% of the profit for handling payments. The advantage of using this is that you don't need to worry about keeping up with security

standards which are required when dealing with peoples personal information.