Just tried, got a wallpaper and 160 points. ^^ As tempting as it is to use the many other e-mails in my possession, I'm kinda hoping I actually get lucky enough to win a grand prize, and I'm pretty sure if I do, I'd rather not risk getting disqualified over entering with other e-mails. But we'll see. I was originally concerned that they'd only give the MSP points to your live account connected with the e-mail you used, but I suppose that doesn't make sense. Chances are it'll be a 25-digit code e-mailed to you, but what if one XBL account uses codes from multiple e-mails?