Also, guys, on Amazon, it's not called hourly bestsellers, that's just what we call it. On Amazon, it's simply called "Amazon bestsellers" and described as "Our most popular products based on sales. Updated hourly."
The arrows are based on rankings from 24 hours earlier. They have nothing to do with sales in correlation to last hour. Just look at the PSN cards, do you think all three of them sell exactly the same every hour?
And pay attention to te PS4, unless it falls to number 9, the red arrow will dissapear soon. How do I know this? Well, either I'm a psycic, or the way I described above is how the list works