Having worked at a couple of ecommerce companies on the software development side I did the implementation and financial analysis of a lot of these methods. I had never really studied them, and when presented with "this is what we need" I thought it was amusing that the marketing team thought they would work, and I wound up extremely surprised at how well they did.
Incrementally adjusting price points over a few weeks before a big "sale" so that the sale price was actually more than the original price was one of the dirtiest I saw, and it worked better than any of the others. The other was curating a list of items that the company had too many of and which weren't selling at all and putting them on a "hot" items list to get customers to buy up all of the extra stock was one they used all of the time.
Oh yeah, they love doing that. Slowly increasing the price by 20% before a sales period and then showing off that they have 30% discounts....