When faced with the unknown, the human brain goes into information acquisition mode, looking for clues and cues to decide how to act. Stage magicians and mentalists will sometimes vary the height of the steps their subjects climb to join them onstage. Neuro-linguistic programming practitioners will shake someone’s hand in an unusual way. The resulting unfamiliarity makes a person more open to new information, and more suggestible.

The Top Shelf strategy puts this to work. If you’re an unknown brand, surround yourself with prestigious peers to increase your perceived value. Partnerships, memberships, alliances and advisory boards all confer a halo of respectability. Unable to taste a wine beforehand, buyers rely on the shape and weight of a wine bottle, the quality of its label, and its price as substitutes for quality.

Think about the last time you visited a bar: If you see four premium brands on the top shelf of a bar, and a fifth, unknown, brand alongside them, you’ll infer that the fifth brand is of similar quality. You don’t know what makes the new brand special, so you rely on other cues to determine value.

To help dating app Bumble spread on campus, the company put up signs all over universities that told students not to use Facebook, Instagram, Snapchat, and Bumble. Bumble realized that university walls were an unregulated medium, and that cleaners and administrators were unlikely to remove an official-looking sign that criticized social media platform.

Students saw four “forbidden” apps, and knew what three of them were. This sparked curiosity about Bumble, and elevated it by association with other popular mainstream apps.

Startup marketers should be asking how they can spark curiosity and gain legitimacy by associating themselves with known, proven brands—and looking for unregulated mediums in which to promote such associations.