I see many who see (or are sold?) software as a magical solution. Without good data and defined business processes (workflow, ownership etc...) success is elusive.
Agreed with the lower-cost CSP options listed above. But also consider the fact that a CSP is only as good as the data you put into it, and the time you take to configure and maintain it. If you don't have the budget for Gainsight or ChurnZero, then consider a lower-cost CSP (list above) but ALSO recommend hiring a fractional CSP admin to help you implement it. Otherwise, you risk it sitting there gathering dust.
Naomi