How do you react if a prospect goes dark on you?

"I know that sometimes a prospect who seems great might end up not working out, for whatever reason. I don't take it personally, because I know that there are plenty of valid reasons they may have changed their mind. For example, perhaps they don't have the funding to pay for the product or service, maybe they've lost interest in it, or perhaps there are other external factors in play that explain why they've suddenly discontinued their communication with me. If I believe that the prospect had a sincere interest in the product or service initially, I make sure to follow up several times before giving up on them. Sometimes it's as simple as the person is busy, and they need a few reminders before they are willing to move forward."