It’s a very simple promotion at the core. Spend money for cash shop currency now while the game is in beta, and you can spend it freely within the cash shop in this test phase. Since the servers will be wiped, all of that money will be refunded to you after this test, but 15% extra on top of what you would normally get. So you get the money back and more besides, which is a pretty good deal if there’s stuff you already know you want to buy when the game goes live.
Revelation Online is running, and you can test out the game’s cash shop right now if you’re in the testing. But maybe you’d like to spend some money on the game while it’s testing? Aside from buying a Founder’s Pack, or possibly in addition to it. Because the game wants you to spend a bit more money, and it’s enticing you to do so by… giving you money.
Source: Official Site