Do notice that the method of calculation isn't actually mentionned for th hourly updates (just that it gets recalculated every hour.) Could be some kind of continuous function, with recency gaining traction, but high sales from 2 days ago also having an effect.

I doubt that they are manually pinning certain items.

Whats Wrong with Arms?

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.

Where have you been for the last few months? Don't make the mistake of thinking this is some 'fanboy' drivel, this is a concern I've had with Amazon for ages now and but for Dec would have stopped updating the charts. I'm still not convinced Amazon is back to normal because what we're seeing here shouldn't (IMO) be happening.

Thank you, I was just about to post something like this, but you pretty much summed it up. Amazon is the easiest place to reserve systems like Switch, so I'm sure they did a large amount of sales when it was available. As you said, other items have sold a large amount, sold out, and then remained at the top of the charts for days (Amiibos come to mind, as do certain Xbox and PS4 sales during Black Friday and Cyber Monday and such). 

Also (not just to Welfare, but in general) unless the Switch is going to completely tank (unlikely), of course it's going to top the charts for a time. It's a new system (not just an upgrade to an already existing system with a very capable cheaper option, like the Pro and, likely, Scorpio) by a company that has been regaining some popularity over the last year, it had better have a good launch. Whether it gains any momentum from that launch or begins to waver, like the Wii U did, remains to be seen. 

I dont know.People said the same thing about Splatoon and look at what happened.I think ARMS has the potential to repeat that in my opinion.People already have a really good impression with what was shown(including hands on impression) and if they come and say that it has a good single player and it has other modes that I think they said it has, with a good marketing push it could sell really well and who knows, push some consoles

People are trying to downplay the Switch so hard. But you know what? The thing definitely gets the attention of people. Not just here and in other gaming forums, also in social media and YouTube. EVERYONE is talking about the damn thing, that's free PR right there.

Ok, there are a lot of negative voices. But I remember a little thing that was announced 10 years ago. A little device that was discussed everywhere to death and many people hat a whole loz of reasons why the device will fail big time. The thing I'm talking about was called iPhone.

No need for a conspiracy theory here. Obviously Amazon is using a smoothing formula for its charts. NiS obviously outordered the next best thing by magnitudes initially, hence the thing can stay on top of the list for many hours, even several days depending on the formula.

I'm more interested in seeing if they put the necessary emphasis on the fact ARMS has both morion and traditional controls.  That will be key to it reaching its full potential.

It's par of the course for all new systems. The most important aspect is the longevity.