If a busi­ness is exper­i­ment­ing with vol­un­tary pric­ing (‘pay-what-you-want’ pric­ing), to increase sales and prof­its give a por­tion of vol­un­tary pay­ments away to char­ity (and adver­tise the fact, naturally).

That’s the con­clu­sion from a study by researcher Ayelet Gneezy com­par­ing a num­ber of pric­ing plans involving–in var­i­ous combinations–voluntary pay­ments, fixed prices and char­i­ta­ble donations:

At a theme park, Gneezy con­ducted a mas­sive study of over 113,000 peo­ple who had to choose whether to buy a photo of them­selves on a roller coaster. They were given one of four pric­ing plans. Under the basic one, when they were asked to pay a flat fee of $12.95 for the photo, only 0.5% of them did so.

When they could pay what they wanted, sales sky­rock­eted and 8.4% took a photo, almost 17 times more than before. But on aver­age, the tight-fisted cus­tomers paid a measly $0.92 for the photo, which barely cov­ered the cost of print­ing and actively sell­ing one. […]

When Gneezy told cus­tomers that half of the $12.95 price tag would go to char­ity, only 0.57% rid­ers bought a photo – a pathetic increase over the stan­dard price plan. […]

But when cus­tomers could pay what they wanted in the knowl­edge that half of that would go to char­ity, sales and prof­its went through the roof. Around 4.5% of the cus­tomers asked for a photo (up 9 times from the stan­dard price plan), and on aver­age, each one paid $5.33 for the priv­i­lege. Even after tak­ing away the char­i­ta­ble dona­tions, that still left Gneezy with a decent profit.

The researcher calls this “shared social respon­si­bil­ity” (in com­par­i­son to plain old cor­po­rate social responsibility).