Prospecting databases exist with technology information garnered from web caching. We work with a file that has almost 8,000 selectable deployed technologies at a company level. Common tactics I see include targeting competitive products and targeting base systems required for bolt on technologies.

If you're already using a marketing automation solution, you might try testing prospecting email records to opt user's in to your content then building a relationship and conversation from there.

Always free for a call if you want to explore the idea more.