Backstory: Lately I've worked with mainly shopify customers and almost all of them are missing or lack clarity in their email notifications.
The Idea: Done for you shopify email notifications.
Deep Dive: Customers would install a shopify plugin, granting you the appropriate accesses and you would draft any missing emails. Additionally you would provide a congruent voice and message across all emails.
Validation: The number of $1M+ ARR companies without proper email notifications is shocking.
Monetization: This is a one and done service. Ideally you would provide enough value to the customer which would lead to more work.
Steps to Launch: As with most productized services, you would find a client that would need these emails and then create a mvp plugin and get them to use it to prove out the concept.