I'm pretty sure that we gamers have already tried getting free card codes online for our 3DS, iTunes, PSN, and it never worked.... Until I found this site. The link is here: http://wamjelly.com/?ref=1320726
Basically, how it works is you give someone your link that you get when you go onto/join the site and share it with others for one point.
And by now you're probably thinking "Oh nooo, no, NO! What do I need for something, 500 points? -___-". And you'd be right, but you're wrong. XD
For example, for a $15 Dollar E-shop card you only need five points. FIVE. So after five people click your link, you can get a $15 dollar E-shop card. WOW.
I hate to sound like a self-promoting moron, and I haven't actually seen what happens when you get enough points for anything, but if enough people on here click my link + spread their own, we can verify if this site really works.
The reason I worded the title is because I REALLY think that this site will work. It looks legit, is updated to 2016, and so on so forth. Try it out! You might be surprised. =)