[huwshimi]

It might also be worth checking out http://sourced.tech/ as they seem to be doing something similar.

I know of sourced.tech as they contacted me about a position recently, but the job they contacted me about wasn't relevant enough to my skills and experience.

Your competitive advantage will probably be in the quality of the target lists you create. If you can nail that on a broad scale you'll have something with a lot of potential (this is probably also the hardest problem).

I'd consider starting by running some experiments for how to create relevant target lists.