Hello, my name is Erik and as a Senior Analyst Programmer in marketing I had the opportunity to build targeted leads list for sales agent, witch is quite similar to your goal with this question. You are on good track with your suggestion of using multiple models to determine your "customers" pot...
I would suggest the first question to ask is "what problem do I solve?" And of those people I solve problems for "who do I create the most value for?" In the non-profit world you need to add "How does my business help the non-profit run better and/or help the group the non-profit focuses on?" Fo...
You can work upon one of the many tools that exist for this exact purpose: 1. You can use aMember to create a standalone membership website. 2. You can setup a Wordpress website and install a plugin like "MemberPress", "Paid Memberships Pro" or a combination of plugins like "Woocommerce + Groups...
Betalist and similar startup "launch" sites house a pretty updated list of software-based products that are being built. Betalist in particular is for beta level software projects, so at the point when they'd be looking for these types of solutions.