This post brought to you by the numbers seven and twelve

It has long been held that there are seven basic plots in literature. It is also sometimes claimed that there are also only seven basic jokes (and as Alexei Sayle once said, six of them are about jelly). So is it really the case that advertisements need twelve whole categories of their own (Slate), almost twice as many as either fiction or humour? Apparently so. I think the point about a society that needs twice as many categories of advertisement as it needs categories of fiction or humour pretty much makes itself.