Like anything, it's a business. The more conventions and speakers, the greater the profit. All you need is 10 grand and a dream. Maybe 1 of 20 are decent.
I've heard better ideas come from getbig. The Ted talks are usually a group of high intellect people circle jerking to problem that never get solves and welcome "far out" ideas.
Like a cat chasing it's tale.
"What if we could all be connected, all the time, anywhere in the world? No, I'm not talking about the internet...I'm talking about a universal hot air balloon that anyone can buy...for just 60 grand. It has a special satellite built in where you can just speak and others riding on hot air balloons can just hear you. Pretty cool right."
Some ideas do yield results and are sound...rare, but it's usually a bunch of rich guys sitting around bored thinking up goofy shit.
One Ted Talk featured this guy talking about school lunches and how much sugar kids consumed. He did the ol' "pour the wheel barrel of sugar on the ground" bit, but took a year's worth of sugar when demonstrating. If you take a year's worth of anything and combine it into one barrel, it's a gross amount. Imagine stacking chicken breasts or putting eggs in a large bowl. It's would be almost 3000 eggs.
Point being...it's goofy shit that usually serves no point. You know, much like getbig. Maybe I should attend next year.