Backstory: Many businesses that do cold-calling are getting their leads from terrible sources. They might purchase a database of old names, and sort through and call the 'relevant' people on that list. Cold-calling is a numbers game, and stale leads don't help those numbers. There's a demand for businesses that generates quality leads as a service.
The Idea: Lead-generation as a service.
Deep Dive: There's a few companies out there that do lead-generation as a service right now. But not many of them are doing it well. If I were to use this service, an example of something that I might ask for is:
"I want the emails of 500 people who hold CXO positions at companies that have a Shopify store."
The key to making this work is to get a streamlined process down for delivering quality leads quickly and efficiently. Here's how I would tackle getting leads for the example above:
The above way is the manual, slow way. Eventually, it would be great to write tools that automate this or speed up the process. I would advise validating the idea first, and then building the automation after you need to scale up.
Validation: There's always a need for businesses to have new leads.
Monetization: I think you could charge a pretty penny for this. I would imagine that a developer who just released a Shopify widget would pay good money for access to this information. That's just one example though.