If you go into a store looking for an item on sale and the shelf is bare, always ask for them to check the back. 6 times out of 10 I have been successful at getting what I wanted. If they don’t have any in the back, ask for a rain check!!!
Most stores do give out rain checks, however some store do not offer them and some sales ads for certain items will specifically say “no rain checks” (even at stores that offer rain checks on other items).
Also most rain checks will have an expiration date so make sure you use it before it expires and make sure that if you are going to use a coupon for the sale, that the coupon will still be good by the time you use your rain check. If the coupon is about to expire, ask for them to write on the rain check that the coupon was good at the time you got the rain check (not all stores will do this).
***Just an FYI, I know for sure that Walgreen’s, CVS, Publix, Winn Dixie and Albertsons all give rain checks.