I think it'd be difficult to guarantee that someone great at talking in-depth on a technical topic (most technical speakers) could do so for a range of audience

I think it'd be difficult to guarantee that someone great at talking in-depth on a technical topic (most technical speakers) could do so for a range of audiences, which could make selling the speakers difficult. Yet, I do see the potential in this kind of matchmaking, especially if you get some big names on board early. I've only recently started doing 'proper' public speaking myself, after a varied history in acting, improvisation, coding and a failed attempt at student politics. It's a lot of fun, and my sort-of-plan is to get the rest of the year's gigs under my belt and then see if I feel confident/ready to charge, as I'm not being paid (just expenses covered) so far. To be honest, though, if I get a conference ticket and expenses out of it, that's fine for me right now..