I imagine it's getting a Prime Day deal.

Went through the list, but couldn't find any deals for the console. So it probably has more to do that there simply ain't much exiting stuff having released in the last couple weeks on the other consoles. Of the top 20, there are a whooping 9 Switch games, but only one XBO (crash bandicoot) and 2 PS4 (GoW and FC5).

In other words, evergreens plus new releases during a drought on the other consoles trumps UK's lack of excitement for Nintendo consoles.

There were two UK prime day deals, one sold out and the other is about half-way claimed.

https://www.amazon.co.uk/dp/B07F8HZV7K
https://www.amazon.co.uk/dp/B07F2YGBSD

Top 3 all consoles. Indeed they were bundled. But as a standalone it wasn't. Still cool to see it upfront 

Even worse here, the Prime "deals" are the exact same price than if you would go and buy them separately - at full price, mind you! So it's no deal, it's a bundling at best.

Nah, they were actual deals. They were lightning deals so they expired.

They were each around 339 pound sterling, about ~40 pound savings.

EDIT: http://www.nintendolife.com/news/2018/07/deals_grab_a_bargain_on_nintendo_switch_goodies_on_amazon_prime_day_in_the_uk has the details.

"We've added the direct links below so make sure to grab yourself a bargain. As you can see, the deals have now dropped to £329.99 and £339.99 respectively, saving around 13% on the asking price. "

Ah okay, nevermind then.

45 pounds off, that's basically throwing the game in for free

The deals are kicking in!

Snagged the $149 3DS, great deal

And Amazon went back to the old design yet again.

Seriously, at this point Amazon is even more undecided than my wife