In general there are two types of fee for online ticketing
1. Ticketing Fee :
Ticketing fee is the minimum cost to use ticketing software online.
Fee to use ticketing system to sell tickets online. Most ticketing platform operated on per ticket sold fee model.
For example fee to use FEARTICKET is just 50 cents per ticket sold online and No Fee for Box-Office ticket sell using iOS/Android Box-Office App. It's flat and simple per ticket fee and no other fee.
2. Card Payment Processing Fees:
A cost to use "Payment Gateway" for processing online credit or debit card payment.
Online credit card payment gateway fee to receive payment for your tickets sell in your account.
Depend on which payment gateway you are with to receive payment from your ticket buyers.
Example: - Standard fee per transaction is 2.9% of total amount + 30 cents, can be much lesser too.