Amazon doesn't manipulate the hourly charts. Hourly's aren't an exact placement and we have had situations where an item is out of stock but take a while to start dropping. Switch probably got preordered so much that it is still considered a top selling product days later because of how the hourly charts actually work. If I had to guess, the hourly's are actually more of trend of how well an item sells compared to everything else for a certain period of time, and not direct unit sales for the last hour.
Won bet with t3mporary_126 - I correctly predicted that the Wii U's LTD at the end of 2014 would be closer to 9 million than 10 million. http://gamrconnect.vgchartz.com/post.php?id=6673287