Advertising is the industry that people who were not lucky enough to get actual "creative" jobs end up in. These people—creative people whose artistic or literary dreams did not work out, often due to economic forces far beyond their control—find themselves in a position in which they are obliged to use their creative talents for purely commercial ends. Selling soap, so to speak. This causes quite a bit of cognitive dissonance. These people therefore expend quite a bit of time and effort justifying the position they find themselves in, in life. (As do we all!) Having justified their position to themselves, they seek to bolster their justification by attracting others like themselves into their same field. The more creative artists who do advertising for a living, the more of a real, justifiable, creative career it must be. They therefore use their considerable creative talents to sell the field of advertising itself, to their peers.