It's understanding their drivers for considering participating in a program, how they are already promoting their own successes, what business needs are they hoping you can help with, and what are their personal motivations...once you get a deeper understanding of that (and they feel heard), it makes it more straight forward as to what levers to pull and what opportunities to focus on most.
And I think it's a response that resonates most with the sales orgs when they get involved in the hiring process.
Bigger though, I think it's a question that a lot of customer marketers are trying to answer in their own roles.
