A few observations:
• C-level executives tend to be the busiest tier. That doesn’t mean there is no chance—it just means you may need to reach out to more people to get a yes.
• Shared contacts help. They add credibility.
• Working in the same function—or having anything else in common—is a plus.
• Trainers, coaches, and professionals who do this for a living are less likely to respond (or they may direct you to their services, which is fair 🙂).
• A success rate between 10% and 30% is achievable for people outside your network. For people you personally know, the reply rate should be 50% or more.