Ad industry groups lay out 'guidelines' for 'legitimate' marketing from 'vulgar' spam. When was the last time guidelines prevented a massive coordination failure? The problem, folks, is in the micro(economics). The incentives are all wrong - spammers pay nothing, but make something. Hence, spam. It's really that simple.
Guidelines won't do a thing. These groups should be taken to task for wasting their members' time and money.