SAUSALITO, Calif. - Tip jars have become ubiquitous fixture at an ever-widening array of retail locations, from dry cleaning to takeout food and nearly every place in between, the San Francisco Chronicle reports.

While restaurant-goers know tipping is expected as part of the experience, finding a tip jar at other service counters can be jarring to some customers. Some retailers at place that haven??t traditionally accepted tips say the extra income is becoming expected.

"Tips end up being a substantial part of the income for the people who work the counter," said Jay Foster, owner of Little Skillet takeout window. "I think that most people come here and spend $10, and tip a dollar or two," which is around 15 percent of the bill.

Coffeehouses have begun to expect customers to place a little something in jars or cans by the registers. Amy, who works at a coffeehouse and only gave her first name, said, "You always tip when you're at a bar ?? but I think it's a new thing for coffee. People are just starting to realize that they should tip on it, too."

Most patrons agree that whatever they tip should have a tie to the service received. But some still balk at tipping carryout orders ?" and some restaurateurs concur.

"Most people who take to-go food don??t think they should tip," said Umberto Stoll, who co-owns Perbacco and Barbacco restaurants. "I think the general public feels that they??re not really getting service, because the kitchen is making the food."