Smart people always vastly overestimate the technical interest level of their audience. Even in audiences composed exclusively of brilliant, technical people, the average level of commitment to whatever you're saying is damned near zero. Accordingly, you must keep your message exceedingly simple. Thinking is hard for everyone, and you have to persuade people to do it. It doesn't come for free.

You may not like "marketing", but you're giving a talk to sell a vision. Always. Once you win people over, they'll seek out the details for themselves.