Author and former adman Ken Segall argues that Apple may have lost its edge in when it comes to marketing. Segall, who helped develop Apple’s famous “Think Different” campaign in the late 1990s, points out that the days of Apple’s humorous “Get a Mac” campaign are long gone, and that the new era of product-focused marketing favored in Cupertino is proving far less effective against mobile rival Samsung. While you can still argue that Macs and i-devices have a ton…