I think it depends on the concept and execution. Two fine examples of each: A Luke Sullivan ad in "Hey Whipple..." for a hair salon. Two words- "Bow," and "Wow." "Bow" was crossed out with a single stroke of an editor's red pencil. Another for a Colgate ad - a yellow happy face with the tube creating the smile line. But, to get attention, I think the graphics/layout have to be appealing. The copy can be the most complelling in the world, but if the layout's not designed well, few will read it.