Great question, and this article echoes the answer below: http://www.slate.com/articles/news_and_politics/explainer/2012/03/why_are_there_so_many_mattress_ads_

Great question, and this article echoes the answer below: http://www.slate.com/articles/news_and_politics/explainer/2012/03/why_are_there_so_many_mattress_ads_on_the_radio_.html http://www.slate.com/articles/news_and_politics/explainer/20... But then: why not as many furniture ads?