There’s wide debate in the customer success discipline regarding the best structure for a CSM compensation plan. Typically, I see the following three CSM compensation models:

Base Only – pure base salary with no bonus or variable component
Base + Bonus – base salary with a small bonus structure, usually in the form of a Management by Objective (MBO) bonus
Base + Variable – base salary with a variable component to not only reward for performance, but also to provide more upside for over-achievement against targets.