I have had many reactions from clerks over the years.
Highs to lows and everything in between.
From the event at Torrid where the sa suggested I try on the dress I was buying. Very nice gal.
To an annoying event at Walmart where I was buying a few items and picked up a pair of leggings. The cashier started acting real strange, asking me if the leggings were mine and walking back and forth. It was weird to watch her.
Most stores want to sell a product. If the CD community has enough of a presents that it is noticeable, then it is money in there pocket to be helpful.