Anyone who's been in marketing for a while knows all about the 4 Ps: product, pricing, placement, promotion. Of course. For many, they're the underpinnings of marketing and still remain a point of reference. But social media marketing involves another P, that is, a fifth P: people. Never as much as in social media marketing has the starting point been people, that is, what they say and the opinions they share. Many people still think that all you need is a well-put together company website, a few leaflets, and some banners to bring in sales and profits. They're quite wrong. It's time to stat thinking about the fifth P, the semantic web, social media, search engines, hunches...