Well Splatoon was one of the greatest games of 2015 and one of the freshest new IP's on any platform for a long time.

Did Splatoon tempt you into finally buying a Wii U?

Maybe it didn't quite tempt you enough to purchase a Wii U but it did get you interested in the prospect of Nintendo's next hardware, The NX? With potentially more fresh new IP's and Splatoon in the future?

Or maybe you had a Wii U sitting on the back bench already and it got you to bring it back out to play?

Myself I had always followed the hype and sales of Splatoon since it launched and whilst not owning a Wii U until I decided around Christmas to take the plunge and grab a new console and the decision came largely around the success of Splatoon and a little bit of XCX, It did not disappoint and some of the most fun I've had in many years came from the Wii U and Splatoon.

No, not really. Tried the game at a friend's house, and while it is good, it doesn't entice me to buy a whole system. I'm more interested in getting a WiiU for Fatal Frame 5, TW101, Devil's Third, XCX and Lost Reavers, to be honest.

I already had a wii u, but didn't bother to get it. I have played it a couple of times at a friends house, but it was okay. I wouldn't really call it the greatest thing this gen by a long shot

No, didn't like Splatoon.

I already had my Wii U since 2013, but I did pick it up.
Loved the campaign, although short had one of the more fun/challenging final bosses in a while.

Multiplayer is always a good time though it can be very frustrating D:

I'm not really into multiplayer games honestly, i'm more of a single player campaign guy.

Played it a couple of times and it was fun, still a multiplayer shooter though and i just can't seem to enjoy them for more than a couple of hours.

Great game, just not my cup of tea.

Already had a Wii U but i didn't buy it, played it at a friends house.

"Did Splatoon have any effect on your decision to buy a Wii U?"

Nope.
Got the Wii U way waaay before Splatoon was out.

"Did get you interested in the prospect of Nintendo's next hardware, The NX?"

Nope.

What will is a traditional 3D platformer of mario (galaxy,sunshine,64), and a Zelda game though.

Maybe some real paper mario games? you know the basic turn based rpg ones? yep that would help too.

I got the Wii U before it was announced so no

As for the NX, no since I don't know anything about that console

Not at all, when Splatoon was announced I found it interesting but when the actualy hype started building around it in 2015 the NX was already announced so I already made my decision of skipping on Wii U, still I'm looking forward to whatever Splatoon-related content on NX wether it's a port or Spla2n, I can see it becoming my 3rd/4th favourite series...

I bought my Wii U prior to E3 2014, so no.