Landing page vs The actual site

You know Quora, right?
So, imagine something like Quora, but with a business model centered around charging for A2As (ask to answer) .
What should they show to their new visitors?

They could make a nice landing page explaining what the site is about, and the paid A2As. But then, people wouldn't see the main strength of the site -the content and community- right away; resulting possibly in low retention.

Or, they could show the actual site, with the questions and answers. But the problem there is that they really want people to know and understand the A2A feature, because it's how they make money, and it's the main thing that differentiates them from the competition.

What would you do?