I would love some clarity on how they plan to be sustainable. In the FAQs they claim
"We are currently focused on bringing the best possible service to you, completely free.", which makes me sad. If they deliver a value they should charge something.
I can understand not wanting to communicate on a business model that isn't ready but could you maybe point out some leads other than the usual ads or data-selling business ?
Or if you don't want to be specific maybe you can point out that you are definitely against selling user data later on even if it means saving the company ?
I was happy to find a "How does Coffee Chat make money?" section but it's content isn't very helpfull if you're a user fearing data collection and adds.
Edit: maybe you can make it official on the website?
I've participated in a number of schemes aiming at sharing expertise in the past and would be glad to share and get some on your platform but, as others have stated, I think that to see traction, you'll need to specify a business model else everyone will be inclined to "if it's free, you're product" mentality.
I'm not distrusting your current statement of "no data sharing" and, if I may, "won't do evil" mentality but in this day and age, customers will need a clearer statement right on the product page for it to be trusted.
A quick and easy alternative would be "Currently in beta and free for all until December 31, 2018" would probably assuage some fears, with expectation of a coming bizmo, whatever that would be.