I don't know definitively, but I'm going to guess that the founders of these sites already had some healthy networks and connections upon starting their businesses. Given that both are venture backed, it's likely that helped as well. It only takes a few big names before the dominos start to fall because of the value of (a) those names asking other names in their networks and (b) name dropping one to another. Let's say you had a good connection to get Cuban on your platform as a favor. Once you told others that Cuban was on it they'd have to pay attention, so there's an elite network effect.

I'll tell you this: One of my podcasts set out to interview the biggest and baddest founders around and we... just called them. They saw the PR value and they did the interviews. They had no idea who we were and they just did it for us. You never know until you ask.

In the case of Clarity, I think it's also good that it solves a real problem of everyone wanting to have "coffee" or "ask one question" of these guys. It puts a market value behind that to control the demand and supply mismatch. It's a good value for a lot of us (not that I'm in that league) who have to constantly give free or cheap advice because it's hard to monetize the little snippets of value that get handed over in a basic networking conversation.

All that said, I think if you have a real business value to give then that should lead your messaging as you reach out to the big guys. Happy to help you hone that.