Oh, DEFINITELY ask Clarity for help on how they target their customers and make their money.
C'mon man, would you give that information away? It's called Intellectual Property and Competitive Advantage.
What you should be concentrating on, if you're interested in having a similar business, is the Barrier To Entry.
Your scope is far too wide right now. "Online advice"? Niche it down. You can always expand later, but for now a generalist approach is not going to attract a target market.
The tech, you'll find, is the easy part.
Attracting experts and inquiries...that's another story.
There's the barrier to entry into this market. A minor part of it is putting up the tech...the major part is attracting experts and drawing traffic from those wanting to ask questions of said experts.
You will need systems in place for both objectives. And numbers to support them. How many experts do you need on your platform? And how many people booking calls to them to support your revenue target? And how many people visiting the site to book one call? Lots of freebie seekers out there. Last two inquiries I've had have run once they saw my (publicly displayed) fee. Kind of funny and fortunately not relevant to me as I have real businesses.
Or maybe this is a homework question for you? In that case, you again should niche down, and look for data on those niches. It'll be much easier to find. Maybe target the three or four most popular niches of questions people ask about and add them up. 80/20 Rule, y'know.