If someone is qualified, seemed interested in your deal, but for whatever reason they ghost you and stop responding to you, send them the following final text:
"Did you not want me to follow up with you on this anymore? "
Variation: "Is this still a priority for you? "
This will elicit a response about 90% of the time.
There are several things going on here:
1. You are removing a perceived offer/opportunity from the table.
2. You're asking a question and it can feel awkward to leave a question unanswered.
3. It's not threatening, unprofessional, pushy, or crying of desperation.
4. If you've built some rapport and value with them they will likely want to preserve the relationship with you.
5. If they don't answer you have your answer (at least in the short term). Keep them on your email distribution unless they unsubscribe and focus your energy elsewhere.
A Yes and a No are both good.
A maybe (aka silence) expends mental energy and time and can act like an anchor that drags down your productivity.
Hope this helps someone.