Whatever you are building, you need to explain to users “where they use it for?” In short, use cases should be very clear.
You are selling ideas and vision. If they figure out how to use it, they will get that outcome.
For example: If you are selling Mobile AD Intelligence ( voice of share of any ad networks), you need a list for use cases for every single industry and people who might be interested in it. After they start to use it, you will expand those use cases learning by their usage. Maybe they are doing something you can’t even imagine it.
You don’t need to explain to every single client why they should have this solution. All you gotta share their peers’ use cases (how others already utilizing it). For example: If you are talking Health & Fitness app size of company 25-50 people who are making spending yearly $5-10M for User Acquisition based in San Francisco, you should get ready to share the top 5 relevant use cases for that client.
Use cases should include social proof ( logos for each vertical), testimonials, and best practices.