The reward of a novel invention is enough to keep it going. Look at science. All ideas are published and shared and you don't have this freeloader issue, because the rewards follow innovation even when those innovations are pubically shared. Also take a look at your own work. Chances are you are freeloading on someone else's ideas with everything you do, and there are huge chunks of process that you are only able to do because someone decided to make those ideas freely available to other people.