Here’s an interesting definition of Marketing. I don’t know where it came from or who the author is, but it certainly describes the different disciplines involved in marketing in a succinct and entertaining fashion – tying together advertising, promotion, publicity and PR in the context of one event.
If the circus is coming to town and you paint a sign saying “Circus is coming to Fairgrounds Sunday”, that’s Advertising. If you put the sign on the back of an elephant and walk him through town, that’s a Promotion. If the elephant walks through the Mayor’s flowerbed, that’s Publicity. If you can get the mayor to laugh about it, that’s Public Relations. And if you planned the whole thing, that’s Marketing! – Author Unknown