Didn’t want to hijack the Sale and Promotion hunting thread.
Since amazon is a potential revenue generator for you: Have you thought about making some sort of “on sale” section on the website? Maybe something people could also “search” for or filter for in the browsing overview?
Maybe the activity feed could be shorter and then there is a scrollable & clickable banner and people could potentially even say they only want to see sales for manga or for light novels, etc. 
Afaik, that information is provided by the amazon api but I have no idea how much work something like this would be to implement.
