You love pets or you wouldn’t be reading this. Ditto, supporting pet adoption. And you probably also love chocolate chip cookies. What do these things have to do with one another?

In a classic marketing study conducted back in the 70s, researchers are Columbia University offered their test subjects jars of chocolate chip cookies, and asked them to rate them on how yummy they were.

All the cookies were identical, however, and the jars they were offered contained either ten cookies, or just two.

Amazingly, the two-cookie group gave higher ratings to the cookies than the ten-cookie group — even though they were the exact same cookies.

We can sum up what this has to do with pet adoption in one word: scarcity.

Advertisers have long known that blaring “Limited supply!” or “Hurry before they’re all gone!” on an ad will help drive bodies to their sales event. It’s also what gets people to sleep overnight in line for Black Friday sales, the famed FOMO, or “fear of missing out.”

Scarcity works as a motivator with time, too — that’s why you see so many countdowns on fundraising pleas, or public radio pledge gifts for some specific number of callers who donate above a certain amount.

Although rules are made to be broken and anything can work in the right circumstances, this is why it’s probably not a good idea to tell people your shelter is full to bursting with animals in need of homes.

Instead, try generating some FOMO buzz by throwing a one-day-only adoption event with hugely discounted fees on the first 100 animals (and maybe a free gift “while supplies last,” too!). You can also try some time or amount-limited benefit tied to donations in your next donation drive, or give a cute stuffed animal to the first 25 people who buy tickets to your annual fundraising gala.

But hurry — there are only so many good ideas out there, and you don’t want someone else using them all up!

Also of interest:

Shelter cats and jam: A free, easy trick to get more cats adopted

Don’t miss more innovative ideas for pet fostering, adoption, shelter medicine and stories about how pets make our lives better and happier — sign up here!