Well, it has now been more than half a year since the 2-for-1 and 4-for-2 rates were eliminated - of course without any advance notice whatsoever.
And despite promises to the contrary, this long lasting benefit wasn't replaced with any decent ongoing promotion / benefit whatsoever - just the usual 10%-20% advance purchase discounts etc., i.e. nothing that any of the competing hotel chains don't offer.
I often used to book Carlson (business) hotels in Europe using this rate and given the low occupancy rates on the weekend it often seemed like a win-win. It's too bad that Club Carlson - after several years of improving benefits - has been mostly eliminating benefits during the last ~two years.