Track sale cycles for items.
One of the flyer search engines I've seen recently (which focused almost entirely on Toronto, which was a dealbreaker for me) included a neat function of tracking sale cycles on items, so you could see what the historical high and low sale prices were for an item during a given time frame. The point behind doing this was so you would know whether something was on sale for a decent price, a really good price, or an OMG-STOCK-UP-NOW price.
Thank you for your recommendation. Our crew will be looking into this change. Stay tuned as we develop new features :)
To add to that too, allow users to input the price they would buy a product for so when the price of that product is at or lower than a user's buy price, the user gets notified how many items that week are a "buy".