It means that pure capitalism works. If you have a better idea than your competitors, then you will be more successful than them.

It's a mis-quote of Ralph Waldo Emerson, who never wrote the actual line.. See http://www.uh.edu/engines/epi1163.htm

Build a Better Mousetrap was created on 1964-02-15.

The cast of To Build a Better Mousetrap - 1999 includes: Edward Quirk

In medieval times, the usual sign for a tavern was to hand an uprooted bush over the door. However, like the inventor of the better mousetrap, the purveyor of first-class wine would not need a bush to attract customers; they would beat a path to his door.