IN CLEAR FOCUS: Marketing Week columnist and brand strategist Helen Edwards is the author of "From Marginal To Mainstream." Helen discusses why marginal behaviors, practiced by small population segments, differ from trends and how they can drive product innovation and category growth. Helen also offers strategies for identifying behaviors that have mainstream potential. Listeners receive a 25 percent discount on "From Marginal To Mainstream" at KoganPage.com: use promo code BIGEYE25 at checkout.