Which is more important to a society: the demands of consumers or the dreams of artists, inventors and discoverers?

The dreams of inventors and discoverers are more
important.  This is because these sorts of people come up with things that consumers
would never have dreamed of demanding.

An example of this
would be someone like Bill Gates.  Before Gates created Microsoft (and for some time
after) there was no real demand among consumers for a personal computer.  However, Gates
and Bill Allen had a vision of what could be.  From their vision came personal
computers, which have helped to enrich our lives in ways that we could never have
imagined.

Consumer demand is important, of course.  But
consumers tend to demand things they already have or slight variations on such things. 
For truly important change (like the change to a society that is so based on computers
as ours is) we rely on the dreamers.