Las Vegas Barkers Are the Best in the World.
My daily commute includes a 4 or 5 block walk right to my office in the core of downtown Seattle. Through years of these downtown walks, I've honed my techniques for dealing with signature collectors, beggars, and other petitioners. Most folks get eye contact, a forced smile, and a "Not interested, thanks." which covers a huge variety of their opening gambits.
But in Las Vegas, they have the best barkers in the world. In a mall, one made direct eye contact and excitedly asked "Have you seen it?!?" She went on "The new hair straightening system from blah blah blah?" I was so surprised that I busted out my pointer finger in my defense to add to my firm "Not interested, thanks!".