When do the CPAs/Auditors think it's material?

I'm working on the IT side of a loyalty program. It mostly results in pricing discounts, but for certain tiers of customers, an actual check for real money is sent to them. Please pretend you're on the accounting/auditing side of this effort. What would you like to have the technical people implement such that your job is easier? When does this cross the "it's material" line?