Backstory: My full time job is consulting for ecommerce companies. Most of these companies are under 50M/yr and all of them are suffering from the same problems: cash flow, user acquisition and scaling. At the root of these issues is the fact that they don't truly understand their numbers: revenue, customer acquisition cost (CAC), margins and lifetime value (LTV). My first engagement with every client involves some sort of audit, I find myself doing the same thing over and over again.
The Idea: Ecommerce audit as a service.
Deep Dive: You would build a simple app that would tap into a customers shopify and processor (stripe or braintree) account. Using their sales data and specific company data (margins and customer acquisition cost) you would compute their time to break even or profitability. Using this information you can create informed decisions on where there are issues within the company.
Validation: Currently I manually do this with all my clients. Additionally, almost everyone I meet at smaller ecommerce conferences doesn't know their numbers.
Monetization: You could use this as a tool to help land new clients or you could white label this and license it to other ecommerce agencies to help them land new clients.
Steps to Launch: I would manually create a report that you send to clients and then move slowly into automation as it provides more value and saves you time.