The only thing that really bothers me about this is the 500 point increment limitation. If I wind up spending, say, $75 on the eShop (maybe a full priced retail game and a $15 eShop game), that nets me 750 points. That means I can redeem a $5 discount on my next purchase, but it also means I'll have 250 points sitting there doing nothing until I spend another $25.
It sounds like a nice bonus if you plan on buying all of your games digitally, but it's definitely not the most cost effective thing in the world. If you were looking forward to this simply to save money, physical purchases might be the way to go. If you're planning on going digital anyway, then yeah, I guess this is a nice bonus - as long as you don't mind having to keep spending more money to reach those 500 point increments.