One thing that works for me (palabra.io co-founder here) for them to 'open up' is to upfront let them know that everything they can share is useful and then something like 'I really have no idea about this space, it would be great if you could share your experience and your thoughts'. I think that people usually share more when they feel they are being useful. I wouldn't say something like that on a sales call but it's great when doing customer interviews.
In terms of getting the leads in the first place, I would say connections/people you know. But would love to hear what others are doing.