Marriott properties in Thailand are offering 50% off of one night stay until July 31, 2014. All you need to do is to sign up for Marriott’s Thailand email list.
Note that the discount is likely from the highest available rate and is not always available. You can, however, save quite a bit if there is availability for a date that you are looking at.
You can sign up for the email list here. You need to confirm your subscription by clicking the link on the email that you receive from Marriott. You will the shortly receive the certificate by email that you need to hand in at the time of checking in.
Renaissance Phuket eVoucher Rate Display
This eVoucher rate offered the best price for a date in November that I was searching for.
Searching for the eVoucher rate
When executing the Marriott’s rate search, you need to use corporate/promotional code D58 to bring up this specific rate plan. You can then just do the reservation online.
Remember to reference your certificate number on the comment field IF you make the reservation directly on Marriott.com instead of calling/emailing.
This rate plan is likely available on dates when the properties have surplus inventory. If you have more than one person in your party, you can both sign up for the emails and receive the discount certificate. I came across this offer on FlyerTalk post here.