In Poland, during communist times, there were often shortages of basic necessities at stores. Long lines of people were a signal that something rare was on sale. This led to people getting conditioned that if there is a queue, you get in and wait and only then ask what is being sold.

Queues are much more rare now and when they happen, it's for a different reason. However, I still sometimes get the "What's on sale?" question from passerby's.