Merle Minda walked into the main downtown Minneapolis post office with a package one day last week and got in line behind nine other people.

Fifteen minutes later, she advanced one place. Fifteen minutes after that, her husband came in from the car with a worried look on his face.

"He thought something bad had happened to me," said Minda, a Minneapolis writer. "He'd been waiting for half an hour for something he thought would take five minutes."

Post offices in Minnesota and around the country are jammed during the holiday season as people loaded with packages or in need of stamps confront understaffed service counters.

The U.S. Postal Service expects to deliver 475 million packages over the holidays this year, a 12 percent increase over last year.

"We've seen double-digit increases the past two years," said Pete Nowacki, the USPS spokesman in Minnesota. "Much of that is due to e-commerce."

Unlike retailers and other shippers, the postal system doesn't hire extra people for its counters during the holidays.

"It's difficult to train temporary folks to work the counter just for a season," said Nowacki. "It's a complicated job."

The USPS does hire extra people behind the scenes in the mail processing department and, in mid-December, it adds lobby helpers in post offices to keep lines moving faster. "They steer some customers to the stamps-only lines and make sure people have forms filled out before they get to the counter," Nowacki said.

For many people, the long, slow line at the post office during the holiday season is the most visible effect of the wrenching adjustments the USPS has made to cope with falling mail volumes during the rest of the year.

Because of competitive pressure from private shippers and the spread of e-mail and other electronic messaging, the agency's revenue has been falling since 2008 and volume since 2006. Last year's mail volume was 35 percent lower than in the peak year of 2006.

The agency slashed costs, including many jobs, as a result. At the start of this year, the postal service's full-time employee base was 487,000, 31 percent lower than it was in 2006. Postmaster General Patrick Donahoe has said he plans to trim another 100,000 jobs by 2017.

"You'd think they would be fully staffed for the holidays," Minda said. Though the main post office is her closest full-service option for mailing packages, she doesn't plan to return to it until after the holidays. "I will use FedEx even though it's more expensive," she said.

As the number of employees shrinks, the agency has tried to steer customers away from post office lines. Self-service kiosks open 24/7 have been added at many larger post offices where consumers can weigh their packages, pay for them and have the postage label printed.

Flat-rate boxes and envelopes in post office lobbies are free as long as the item fits and weighs less than 70 pounds. Customers can go online and arrange to have flat-rate boxes and others picked up free by the carrier who delivers mail to their house.

When Jill Schwimmer of Minneapolis wanted to mail a package as she was driving in Edina Tuesday, she asked her smartphone, "Where's the nearest post office?" The response: a Byerly's grocery she was near. "This is faster and more convenient," she said as she waited less than a minute to be helped.

Many grocery stores and gift shops now offer more postal options than selling stamps. The agency directs people to them on its website, usps.com, under "locations" and then "approved postal providers."

Byerly's Edina customer service manager Kathi Jacobs admitted that the lines get longer after Thanksgiving, but people rarely mind. "Our customers always tell us how much they prefer mailing their packages here," she said.

Kimberly Johnson of Minneapolis, who was at the downtown post office to mail letters earlier this week, said she's learned to avoid it during holiday peak times on Thursdays, Fridays and Mondays and also at lunch and near closing time. When possible, she skips lines all together with a simple plan. "I stick to ordering online and my wait is over," she said.

While the front end of the postal experience becomes difficult during the holidays, the USPS has been able to handle the sizable jumps in the actual movement of mail. Even with the huge increase in online ordering and its partnership delivering goods for Amazon.com, the USPS has not experienced the shipping delays that private firms did in recent years. It's even adding Sunday delivery in some areas this year, including the Twin Cities.

Last year, UPS and FedEx were caught off guard when shipments jumped 23 percent the week after Thanksgiving, according to shipment tracking software ShipMatrix Inc. On-time delivery rates fell short of goals and thousands of holiday gifts were delivered after Christmas. Both are pledging to avoid a repeat of last year by hiring more employees and adding shifts this season.

Despite the long lines at post offices, many consumers rate it more highly than UPS and FedEx in overall customer satisfaction and pricing. In a comparison of cost, reliability, selection of services, and overall customer satisfaction by Cheapism.com last year, the USPS won in nearly every category.

"We found that the Postal Service offers the lowest shipping rates overall, whether you need next-day delivery, two-to-three day service or a cheaper option that can take a week or more," the report said.

UPS and FedEx surpassed the postal service in such categories as employee morale, same-day and overnight packages and money-back guaranteed delivery. USPS offers a money-back guarantee on Priority Mail Express packages only.