You can inject the seeds of those ideas while they're enthused about it. In my limited experience it makes people think if nothing else, and best case scenario they start developing thoughts alongf your lines but think they did it all by themselves which seems the best way to get things to stick.
I guess it is a good way to start the little ideas of future technology going... but it just always seems to meet with disinterest with some of them, and the number go up is always what it comes back to.
I just bail out of conversations where it's all number go up, I find them incredibly boring x_x