If you enjoyed your self-checkout experience, you might consider tipping the machine.

Companies such as bakeries and coffee shops, as well as vendors at airports and sports stadiums, are asking customers if they’d like to tip after completing their order — despite not interacting with any employees.

William Michael Lynn, a professor of consumer behavior at Cornell University, said businesses are using the passive request as a way of introducing “tip creep” into everyday transactions.

“Just the prompt, in general, is a bit of emotional blackmail,” Garrett Bemiller, 26, told The Wall Street Journal after he was asked to add a 10% to 20% tip on his $6 water bottle at an airport self-checkout machine.

Experts who spoke with the newspaper said the tips aren’t guaranteed to go to customer-facing workers. That’s because the protections for tipped workers in the federal Fair Labor Standards Act don’t cover tips received through machines.

• Matt Delaney can be reached at mdelaney@washingtontimes.com.