I assume that they make enough money off of them on the front end or we would see reductions in quantities and selection. This is not a low profit business. Also, they outsource their warehousing anyhow so I don't imagine it hurts their cost until they reach a new threshold which I am sure they offset with sales and renew or join today to get x amount of records.
I actually imagine that the profits are tighter on the ROTM because of their exclusivity desires. I imagine that Sturgill and even Madlib were tests of the water to see what it looks like when it isn't truly exclusive from a catalog title standpoint to look at banking on anniversary tagalongs in the future to reduce those costs.