“The marketing industry runs on heuristics, although nobody actually uses that term,” writes Greg Satell at Digital Tonto. “Simple rules of thumb become axioms, which are then dressed up in a new, snappier shell and presented as insights. They are then recycled and reused.” Once these insights gain consensus and momentum, it gets hard for marketers to pivot or evolve, even if evidence against the notion mounts. Here are four such popular marketing concepts that need to be rethought