This is an old promotion, but it's still ongoing and great for people like me who have Hilton HHonors points expiring soon. The first part is very straightforward: simply register your mobile phone and an eligible Visa card and agree to receive up to two special offers each week via text message (messaging and data rates may apply - check with your mobile phone carrier). Just for enrolling, you will earn 1,000 bonus points. You must register between January 20 and June 30, 2012, so there is still plenty of time to take advantage of this offer.
I registered about a week ago, and since the first few confirmation text messages that I received, I have not yet seen any additional texts. You can also choose to opt-out of the enrollment at anytime here (although I would only suggest doing so after receiving the bonus points).
Next, you can also earn an additional 4,000 bonus points by spending a minimum of $100 using your enrolled Visa card at any participating U.S. hotel or resort in the Hilton Worldwide portfolio after enrolling in the program. The spend must be completed by June 30, 2012.
Allow up to six weeks after enrollment for the 1,000 bonus points to post in your Hilton HHonors account, and up to six weeks after completing the minimum spend for the additional 4,000 bonus points to post. You must be a Hilton HHonors member and enter a valid account number when enrolling to receive the bonus points. You can also enroll up to three Visa cards in this promotion (but only one enrollment bonus will be given).
Note that not all Visa cards are eligible for this promotion, including Visa Buxx, Flexible Spending Account (FSA) Visa cards, EBT Visa cards, and other Visa-branded cards whose transactions are not processed through the Visa U.S.A. payment system.