U-M alum Peter Benedek, described by the Internet Movie Database as “one of Hollywood’s most powerful and influential agents,” came up with the idea during a brainstorming session at a meeting of the museum’s National Leadership Council. His and his wife’s foundation pledged to donate 10c for every visitor, up to $30,000 annually for five years, with one stipulation: the museum had to raise at least as much in “non-member related cash donations.”

With 200,000 annual visitors, that means UMMA is in line to get at least $20,000 a year–as long as visitors drop $30,000 into the donation boxes at its three entrances. That’s quite a challenge, since donations in fiscal 2013 totaled just $13,000. So just over a year ago, the museum doubled its suggested donation, from $5 to $10.

“It’s really going to help us a lot,” says museum spokesperson Susanne Kocsis. In fact, it looks as if it already has. Donations rose to $22,000 in fiscal 2014, which ended last July, and this year “we’re expecting double from last year,” she says. With the Benedeks’ threshold cleared, their foundation will then kick in another $20,000 or so, depending on the final visitor count.

“They did expect an increase in donations,” says Kocsis, “but, yes, it has exceeded those expectations, and we’re thrilled with the outcome.”

Like the art museum, the U-M’s Museum of Natural History, Kelsey Museum of Archaeology, and Matthaei Botanical Gardens all have free admission but request donations from visitors. Though the other museums don’t have matching donors, all draw modest but appreciated revenue from the boxes at their doors.

The Kelsey has no suggested donation, but its 24,000 annual visitors drop between $6,000 and $7,000 a year into its two collection boxes, one at each entrance. Associate director Dawn Johnson says the money is specifically designated for educational programs. “It’s a wonderful thing to know that the donations coming into that box go right back into supporting the people who are visiting and the programs they’re attending,” she says.

At the Natural History Museum, 120,000 “general visitors”–i.e., people who weren’t there with school groups or for classes or private parties–left $65,000 in the donation box. That’s a little more than 50 cents per person. While far less than the $6 suggested donation, it’s enough to make visitors to “the dinosaur museum” the university’s most generous.

“Not everyone is making a donation,” says Amy Harris, the museum’s director, “and we’re not complaining about that. We know some people can’t afford to pay, and we’d rather have people come than not come. Our attendance has been going up each year, and so has donation box revenue.”

The money is “important because it’s unrestricted,” she adds. “We can use it for something that wasn’t sponsored by a business or when an opportunity comes up for an exhibit.”

David Betz, visitor operations manager at the Botanical Gardens and Nichols Arboretum, says the former’s donation boxes–one in the conservatory and one at the entrance to the children’s garden–represent “a significant portion of giving.” Attendance and donations have risen steadily since the children’s garden opened six years ago. Spurred in part by last summer’s spectacular blooming of an eighty-year-old American agave plant, the number of visitors at the gardens in 2014 jumped more than 40 percent, to a record 160,000. They left almost $19,000 in the gardens’ donation boxes, up 25 percent over the prior year.

The gardens and the Arb have to deal with one complication that the museums don’t face: the pitfalls of al fresco donation boxes. “It’s a little tricky having them outdoors,” says Bob Grese, director of both. “We tried to have some in the peony garden in the Arb when it was in bloom and had some problems with people trying to steal money.”

“We had some vandalism,” says Betz. “We think it was a theft attempt, although at the Arb, sometimes there’s vandalism just for vandalism’s sake.”