SLH (Small Luxury Hotels of The World) consists of 500+ independent properties and has their own frequent guest program called Club.
SLH just sent an email about their Private Sale for up to 55% off for stays at participating properties between September 19 and December 31, 2013, that are booked by 4PM UK time on September 24.
You can access the web page for this sale here.
Here’s rate display for Esencia in Playa del Carmen
Not sure about the normal prices in Playa del Carmen, but this sale gives a 55% discount from a rather high price. Note that you cannot compare these sale and regular rates at the same time. I had to even open a separate browser to check check all the prices and you should always do the same.
The SLH’s Club doesn’t appear to be a bad program at all and I have been thinking of writing it at some point. Once you get to the Honoured level after 7 stays, you will get a free night cert and and an additional one for every five stays.