I can speak to 25 years ago: the answer is yes. Here are some of the things I saw:
* Marking items up 30-45 days ahead of a big sale. This allowed our price to be 25% off instead of 10%. Or sometimes, our sale price probably should have been the regular price. This happened all the time, and people fell for it hard. Usually this would happen before a 10% off everything sale.
* Price adjustments from competitive shops. All of a sudden on some non-advertised sale day the laser printer would spit out a new low every day price if a strategic product was priced above the competition.
* Some price adjustments occurred to game the competition. We did this a lot with appliances where we'd mark up a model we knew the manufacturer had a ton of inventory. The competition would buy a few truckloads and then we'd run $200 off when they ran their $100 off add.
The only thing the internet has changed is the speed price changes occur and has enabled some other kinds of buy this get that deals.