The Amex / Twitter deals keep coming. Through March 31, 2012, when you tweet #AmexTix50, you can get $50 back one time on your next online purchase of $100 or more at TicketMaster.com with your synced American Express card. Quantities are limited.

For the offer’s full terms, see this link. For an overview of how to sign up for this and other similar Twitter deals, see this post.

Even if you normally wouldn’t purchase tickets through TicketMaster either for yourself or as a gift, there is a way to make a bit of cash off of this offer. One idea is to register for this promotion and purchase a $100 TicketMaster gift card. There is a $2.50 order processing charge, so your total cost would be $102.50. After your $50 statement credit, your real cost for the gift card would be $52.50. Your $100 TicketMaster gift card could then be sold at PlasticJungle.com for up to $87.15 in Amazon credit (or slightly less in cash). That would net you roughly $34 ($87.15 – $52.50) for your trouble.

Note: This offer wasn’t publicized at the time the original list of Amex / Twitter deals was posted, but has since been added.