Oratory, or rhetoric, is the skill of argument or persuasion used by orators. The invention of printing allowed books to be multiplied and produced cheaply. This has made it possible for orators to do their persuasion in print as well as speaking. Adolf Hitler and Winston Churchill are good examples of how orators in the 20th century used media such as radio and movies where once they could only use speech. Both wrote books which sold in large numbers, though Churchill's books were about more than politics. Today television and newspapers play a vital role in deciding elections; the web less so.