Have you been amassing coins as well on your My Nintendo Account? Nintendo tweeted some good news then: come this March you can also use your gold coins to pay for (part of) the Switch games you want to buy!
My coins have seen some good uses, though mostly for the platinum points: I used them to get additional wool and other items in Animal Crossing Pocket Camp, or useful things in Fire Emblem Heroes. But my gold points have been sitting there, unused and expiring one year after I got them.
Starting this March you can buy Switch games with them, with one single Gold Point equal to 1 cent, should you have 1000 Gold coins, you can buy a $10 game, or get a $10 discount towards a more expensive game.
Nintendo will also be changing the way gold coins are earned. You will also be earning 5% gold coins on most purchases made in the eShop. What it comes down to is this: for every $10 you spend on digital games or DLC, you will get 50 cents worth of gold coins in return. This goes for Switch games and for 3DS and WiiU games. 
Nintendo is making buying digital more profitable then buying physical games: you will get only 10 cents worth of gold coins in return when you buy a game cartridge (taking the eShop price of that game as guideline.
I just looked over the game coins that I have….what a pity that 40 of my gold coins expire this february!!