Make sure all URLs are valid, clickable links. Your mailing list service should take care of this for you, but you want to double check and be sure.
Oh god and spell check a hundred times! Mass mailers deserve a second, then third set of eyes. Mistakes in mass emails is not good. I did email marketing for a bit (the good kind where people actually signed up to the list)
I think the subject should be shorter, something like "Pay with Bitcoin and get %15 OFF!"
I would stay away from listing any specific exchanges, such as Gox, and possibly especially Gox lol (I know it's "fine" atm, but still in a general consumers eyes who does not keep up with the day to day of Gox still running, may think that site is still as fucked as it was when it was making the news).
If you have enough staff or like doing cs work over the phone, you could somehow make that "feel free to give us a call at 1-877-486-5650." more or less prominent (either go large or just leave the number in the bottom with your contact). If you go more prominent, something like "Our Non-Comissioned friendly staff is ready to serve you at 1-877-486-5650" .. except not that, that is semi-horrible sounding, but that is the path I mean by more prominent, make that number just that much more appealing (not that they need to call it, but if they do, it will be a little taste of awesome).
Really sounds good and personal though, which it is, so good luck. I'd like to be PM'd conversion numbers after if you don't mind sharing it (seriously too, I love analytics)
