Return on Investment (ROI) of analytical add-ons in SaaS is viewed as the balance of
1) total cost of ownership, including setup, implementation & maintenance, and
2) the value it delivers.
Value could be defined as life time value of customers, growth in users, churn prevention, additional revenue stream options or the competitive advantage.
More unconventional, and less quantifiable measures worth taking into account are: reduced burden on engineering team, overall brand & product perception, increased product stickiness and usage, ...