Dear Albertson's checkout lady,
The store's current promotion is a fine deal: customers receive one stamp for every ten dollars they spend, and when they collect enough stamps they may trade them in for a piece of cookware. I've participated in a few Albertson's promotions in the past. I own a nice chef's knife and a fantastic wok that I use quite a lot.
I know that when a store runs a promotion, the clerks are supposed to enforce the rules. I know that if my total comes to $52.65 I should expect to be given five stamps. If my total comes to $48.73, I expect four stamps.
My total today was $89.91. You gave me eight stamps. I know you're following the rules to the letter, but it was nine cents. I didn't make a big deal about it; I didn't even mention it, in fact. But I'll remember. This might not be the thing that gets me to shop at the Smith's across the street, but enough of these little things can add up to a customer switching stores. Take a little initiative. Make the customer happy with a little extra kindness above and beyond the letter of the law – or promotional rules. No manager in his right mind will fire you, or even reprimand you, for putting a smile on the face of a customer who came nine cents short for a sticker.
Little things count.