If there is one thing guaranteed to get Americans to stand to attention it is cheap Viagra. On June 2nd a firm owned by Mark Cuban, a billionaire investor (as well as a judge on “Shark Tank”, a tv show for budding entrepreneurs, and the owner of an nba basketball team), caused a stir by reducing the price of the blue pill—whose patent expired two years ago—from several dollars a pop to 11 cents. It was one of 87 drugs that the Mark…