Upon recharging, you will receive in-game USD that can be used in the cash shop. Additionally, you will receive a reward upon reaching a milestone, which requires a certain number of accumulated points.  10,000 points is to equal 100 USD in-game.

Your points will accumulate throughout the promotion period.

UPDATE:
List of rewards for July & August ($100-$20,000) has been uploaded.
You can download the PDF version HERE.

PRICE UPDATE (SEPTEMBER 11)