Just the other day, as I was about to order an obscure book from www.Amazon.com, I paused mid-click. I decided to refrain from pulling one more book out of Amazon's warehouse and adding one more box to the already-taxed UPS worldwide shipping system. The book could wait until next year.

That pause would never have happened had I not worked at UPS, and four large retailers, over the past few years. But now I know: Every little bit helps when it comes to keeping boxes off the road in December.

We're a nation of last-minute shoppers, and most of us, caught up in the frenzy of Christmas retailing, see just one side of the equation: long lines, disorganized merchandise and slow service. Several holiday seasons back, I decided to go to the other side, to join the ranks of the workers who allow large retailers to sell as much as they do during this final push of the quarter.

My first stop was UPS, as a driver's assistant, the extra holiday delivery helper in the truck. Delivering packages to the residents of San Francisco, I got a close-up view of the annual UPS push to the finish line that is Dec. 24.

I started at 8 a.m. and ended long after dark. Most days, we would be on and off the truck at least 200 times, drenched in rain if the weather was bad, soaked in sweat regardless. The goal was to have every package in our crammed truck find its way to a doorstep or inside a house by the end of the day.

At Christmas, so many packages flow through UPS that the regular routes are divvied up among more drivers; the usual route's packages won't fit in one truck. If we were lucky, another driver would finish his load first and help us out with what was left in our truck.

On Wednesday, UPS delivered more than 22 million packages on what was expected to be the company's peak 2007 shipping day, which means that UPS workers moved 250 packages each second of that day. The regular flow is 15 million packages each workday. These numbers define the UPS machine, but they just begin to hint at the human toil of people running from truck to doorway and back again.

As I worked the rest of the year through the U.S. retail sector, a writer serving undercover on the front lines of commerce at places like Starbucks, the Apple store and Gap, my goal was to see how companies turned regular workers into believers. As a consumer, you can guess some of what I discovered: The more cohesive a company's culture, the better the product and the service. But even the best get swamped and stressed at Christmas.

This past weekend, for example, the changing rooms at any Gap store had what looked like an avalanche of sweater vests in the bright primary colors of the season. You could walk away, but a crew of workers — at Gap, staff numbers generally double at Christmas — stayed long past closing time to fold and stack.

And when you had to wait an extra 45 seconds this past weekend for a Starbucks triple tall decaf vanilla latte, I hope you appreciated the work-flow efficiency that the coffee seller has mastered, and considered that Starbucks will note the volume it saw in its "point of sales" receipts and will try to turn that data into better barista service next time.

The thing to focus on as you shop is not how bad the service is but how much is actually getting done each minute by people, not robots.

Alex Frankel is the author of "Punching In: The Unauthorized Adventures of a Front-Line Employee." He wrote this commentary for the Los Angeles Times.

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