so, I'm trying to understand how weekly rank is determined. i assumed it was based on sales however my weekly rank was around 800 - 900 steadily for the last half of 2015. suddenly it's down by half.. around 450, for the last few weeks. sales on the other hand remain consistent to what they were when my rank was higher. so there must another determining factor. i recently uploaded a bunch of images that i deleted before indexing because they were editorial in nature and knew they'd be rejected. wondering rejected/deleted files are a factor in the equation. any insight?