So Mario Day is coming up tomorrow, March 10, and Nintendo is celebrating in very menial ways.
One of those celebrations involves a small discount on Mario-related merch, so long as you're willing to jump through a small hoop. Over on My Nintendo you can grab a 20% off discount code for "select Mario merchandise" after forking over 450 Platinum Points. As a reminder, Platinum currency is the easier-to-earn of the two major currencies on the site (the other is Gold and can be exchanged for cash), accrued through various tasks like website scavenger hunts.
So what constitutes "select merchandise?" All of the stuff here, which includes items like clothing, carrying cases, Switch controllers, statues and playing cards. It's not a cornucopia of goods by any stretch, but maybe you'll find something that would serve as a decent birthday gift.
If you need to earn points, just head to the "missions" page. By linking your account to various apps you can easily earn enough. The Yoshi's Crafted World Poochy Pup promo is also still live if you haven't done it already: that's 150 points right there. You can find more details and instructions on how to quickly net those points here.
20% Discount [My Nintendo]