Backstory: Tracking LTV is a pain. Tracking LTV per funnel/ad channel is even worse. Baremetrics does a great job of plugging into Stripe/Braintree and calculating LTV but it's missing a key marketing aspect... what ad/funnel did the customer purchase from?
The Idea: A LTV per funnel tracker.
Deep Dive: You would have to build a platform similar to baremetrics but add pixel tracking as well. You would be able to give customers graphs based on LTV and sales funnels to help their marketing department make better decisions.
Validation: Baremetrics is already a great, well used company.
Monetization: You would charge a monthly fee, similar to most SaaS models. You could scale the fee with amount of revenue.