I mean the public relations industry is all about a few people having an idea and figuring out how to convince lots of people. Just look at how cigarette sales to women were pushed with intentional ad campaigns to change public opinion. They of course need to craft their message in a way that appeals to their audience (for example calling cigarettes "torches of freedom" to appeal to progressive women in the 1920's) but the message "buy cigarettes" is decided by the marketer.
