As a compulsive nibbler and indecisive orderer, afflicted with what my boyfriend terms "Can-I-Have-A-Bite Syndrome," my favorite part of eating ice cream comes before I ever get my cone—free sample time.
I mean, where else do you get to taste something before you buy it? A bakery doesn't rip off a piece of its 3 different baguettes for you to sample. No burger shop will let you try the fries before you order 'em. With the exception of beer and wine bars with obliging servers, ice cream shops are the only places where you can taste before you commit.
And in my taste-maximizing mode, I'm more likely to order flavors I haven't tasted than ones I have—getting to try the dark chocolate chili and the pistachio before I settle on the hazelnut and burnt caramel I knew I'd probably end up with, anyway. Four flavors in one transaction!
I try to keep my sampling down to a reasonable two flavors (particularly if others are waiting behind me)—it would be unseemly to avail myself of many more. But at one of my favorite ice cream shops, The Bent Spoon in Princeton, NJ, sampling is actively encouraged; you're greeted with "What would you like to taste?", the scooper with a tiny spoon already in-hand. After a second sample, a chirpy "You can try more, if you want! Try the whole case!" I've never actually done so, but I've certainly thought about taking them up on that offer.
I realize the sample-before-you-buy model wouldn't really work elsewhere. But man, I wish it did.