Almost signed a contract with a provider that looked cheap on the surface. Glad I first read this acquiring bank article because it walked through all the hidden costs: authorization fees, chargeback penalties, and why interchange rates vary by card type. The section on common acquirer fees helped me spot a monthly maintenance charge that my previous processor never mentioned. I asked better questions during negotiations and ended up with a much cleaner deal. For anyone shopping payment services, don't skip this guide — it's practical, not just theoretical.