In practice, I have not broken down Customer Success costs to distinguish CTR from CTS, @William Buckingham . Most times the debate I had was whether CS costs belonged in CTS (e.g. Cost of Sales) or part of overhead. I think CTS boils down to a question of roles and responsibilities. If a separate team (e.g. Sales) owns up-sell/cross-sell/expansion vs. renewals, then breaking out retention GL's probably makes sense when rolling up separate installed base sales resources to the SG&A line.