Frederick the Great's "potato marketing" is a pretty great story. He was convinced the potato would help grow and nourish the population so he tried to enact it as "people food" via law. The people did not take to it. He then devised the genius plan of having potato fields guarded by soldiers who were secretly told to take naps and/or sleep at night and let people steal the potatoes. People being people some citizens figured it must be valuable and great stuff if it's guarded and the "hot new food of kings" spread pretty quickly.
There's usually potatoes on his grave to this day :)
He did publicity stunts such as potato dinners featuring honorable gusts like Lavoisier and Benjamin Franklin, or (my favorite) surrounding his potato garden with lots of guards... only to instruct them to accept any bribe and be extra sloppy guarding the garden, allowing interested villagers to "steal" the potatoes.