Have you ever purchased so much NX that you needed one of these?

This is a credit card with which you can use on anything. You can use it to buy Nexon Points, you can use it to buy things in a convenience store, you can use it on online stores, etc. When you spend money using your credit card, you save up points (yes, similar to airline miles). When you have 300, 500, or 600 points, you can exchange those points for in-game cash shop items (Meipon tickets, those stamps that increase the number of lines on potential items, merchant permits, protect scrolls, etc.). The credit cards come in three varieties : MapleStory, Mabinogi and Talesweaver. Each type of credit card has different rewards for each game, depending on which they are.

In addition, when you purchase the MapleStory credit card, you will receive a free Phantom Avatar Random Box, which can give one of the special Phantom cash shop items.

I can confirm this, the text in the image actually summarizes it pretty well.

It basically says that there's a new MAPLESTORY VISA CARD! and that you can earn Nexon Points (NX) and in game items as rewards for using it.