The strongest products create behaviors people fondly remember decades later. I have vivid memories of slapping the side of a glass Heinz ketchup bottle at the dinner table. Cool kids knew the move. Tilt the bottle. Tap near the “57.” And wait for the saucy slow-mo avalanche. Losers slapped the bottom and had it splurt out, overshooting their plate half the time. (I still wish I’d learned “the move” earlier in life.) Towards the end of a bottle, my mom had her own trick. She’d pour in a...