The offer of a Retail Sales Incentive is a method used by Suppliers of multiple commodities to switch the costs of supplying one commodity to the consumers of another commodity. The resulting total realized prices of both commodities has to be at least the Supplier’s total economic cost of production of both. And necessarily it has to include the additional cost of the incentive program.
The costs of Loblaw’s “PC Plus” loyalty program is paid by non-program shoppers who pay higher prices.
Governments, of course, use Tax Payer’s money to pay for the rebate programs.