Sneaky pays: the “bar auditing” business is growing fast. Toronto-based Bevinco has sold about 175 U.S. franchises, and it plans to add 500 more pub patrollers and launch a public stock offering. Bevinco’s trying to corner a huge market. About 20 percent of a bar’s sales are unaccounted for because of overpouring, unauthorized freebies or theft. Bevinco says it can reduce that “shrinkage” by 15 percent. (One trick it looks for: “the BYOB,” where a bartender pockets sales from a bottle he’s smuggled in.) Back-of-the-napkin math suggests that if all the establishments in America signed on, they could avoid roughly $10 billion in annual losses.

Covert ops are only one way to keep a bar’s profits from evaporating. If a bar finds Hoffman’s “spot” work useful, it hires him to do weekly inventory checks. Hoffman and crew weigh every ounce of liquor on a scale plugged into a laptop with Bevinco’s software. If the change in weight doesn’t match the week’s receipts, the bar manager asks questions. Richard Eudes did when numbers didn’t add up on sales of champagne and rum at the Wheeltapper, a pub in a Manhattan hotel. Hoffman pointed Eudes to the front desk, which was comping VIPs with bubbly, and to the kitchen, which took rum for dessert sauce. “It adds up,” says Eudes.

It took Bevinco founder Barry Driedger a few tries before anyone was toasting him. He started selling auditing software directly to bars, but managers were too busy to log all that Labatt. Is Driedger doing away with the round on the house? J. K. Kenny, a partner at two Wild Wings Cafes in Georgia using Bevinco, says, “We’re giving bartenders the latitude to be a host.” Shh. Don’t let Hoffman hear you.