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.
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.
Edit: maybe you can make it official on the website?