Ten-year-old Sierra Espie yanks the door open and gets out. Fifty-six pounds doesn't look like much, especially under her loose hoodie and oversized Girl Scout vest. Still, she walks to the mailbox of a good cookie customer to check for mail: A full box usually means that no one's home, explains Diana Espie, her mom, who studies a worn spiral notebook balanced between her lap and the steering wheel.

In the middle of the street, about half dozen children on bikes and big wheels eye the idling minivan blandly.

A little girl breaks from the group of onlookers. She straddles her bicycle — half standing, half sitting — as she slowly rolls forward. The girl hangs over the handle bars like a cherubic tough as she talks to Sierra, who listens, nods politely, turns on her heels and climbs into the van.

Diana, 44, looks up from the notebook, one of two that tracks seven years of purchasing information — from names and addresses to exactly what they bought from year to year, how many dogs they have and what they said when she and Sierra were there last. Before Sierra, her older sister Arielle, now 14, sold cookies for two years.

Sierra doesn't want to go down the driveway. It's the little girl. "She said she was a Girl Scout and not to go back there. She already sold them cookies," Sierra says.

"That's not the point, is it?" her mother says. "They ordered six boxes from us (last year) and they may have bought from her, but if we don't go to the door, you don't find out. Right?"

Like just about everything in this exhausting world of baked goods, perpetual salesmanship and sheer endurance, there's an implicit lesson for Sierra here. It's something about determination, entrepreneurship, maybe even customer service.

Last year Sierra sold 2,748 boxes, ending up the top cookie seller in six Florida counties. Maybe in more than six, but some of the 10 Florida scout councils don't like to single out the big sellers. It sends the wrong message, they say.

Of course, most Girl Scouts won't come close to Sierra's numbers, or her commitment to them. In Florida last year, the average scout sold from 95 to 224 boxes. Little Brown Bakers serves 187 of more than 300 councils nationwide, and its regional rep, Jerry Hill, reports that its nationwide average is 138 boxes per scout.

This year Sierra is shooting for 3,000 packages, which at $3.50 a piece comes to $10,500. About 60 cents of each box directly goes to the troop — in this case, much of it for a trip to Savannah to see Girl Scout founder Juliette Gordon Low's birthplace. The rest pays for council programs and administrative costs.

Sierra has taken orders for more than 1,200. A troop leader and caretaker of all cookie matters for Troop 144 (a cookie mom, in Girl Scout parlance), Diana has asked for 5,000 boxes, which will be stored in her South Fort Myers garage. By mid-February, though, those will effectively be spoken for, prompting another order, this time for 43 cases, or 516 boxes.

Whether its the curriculum for an upcoming troop meeting ("Oh, no, you can't come to a meeting. You'd be too distracting.") or in support of both daughter's plans of dancing professionally, Diana is more than a rock. She's an taskmaster-advocate for qualities that have resurfaced among the child-rearing intellegencia: organization, efficiency, pluck, and, I suspect, the pursuit of perfection whenever possible.

"I don't want anyone to think that they should do what we do," say Diana, who is also a part-time office manager of her daughters' ballet school. The freckles of her cookie-dough complexion crinkle as she frowns. "I'm worried that moms will think they're not doing enough. They do what they can. Most people don't have the time to do what I can."

It's past 4 p.m. on the Saturday before the Super Bowl and the kiddie gang slinks at a distance. Some previous buyers aren't home. Some of those who are home say they've already purchased from a girl in the neighborhood.

But before the Espies leave this dead-end boulevard of rambling, gated McMansions ("DANGER PRIVATE DRIVEWAY"), Sierra will make three sales.

"How surprised are you, Sierra, that you sold on a street where another Girl Scout lives?" Diana asks her as they drive away.

"Zero."

Some Girl Scout rules

• Girl Scouts can't sell cookies alone. Or after dark.

• They must where a scout vest, sash, T-shirt or membership pin.

• They must be accompanied by an adult if you're selling door-to-door and they can never, ever go into someone's home.

'Cookie Divas'

Selling cookies was different when I was a scout in the early '70s. Like most today, I manned booths in front of local grocery stores, but the majority of my selling was a door-to-door campaign of willpower and shoe leather.

My father didn't sell cookies at work. My mom, one of a generation almost comfortable with being called a housewife, waited in the car as my yearning for glory shoved aside my fear of the unknown.

It doesn't happen that way these days.

"There's just not a whole lot of door-to-door now," says Jennifer Paxton, leader of Troop 2083 in Naples.

She doesn't need to explain why. Everyone can imagine the worst, which seems like it's always on the cusp of a fresh headline — if not here, then a somewhere else that looks like here. And then there's the special challenges of Naples, including the profusion of gated communities and retiree residents, many of whom have reached an age where they can no longer eat sugar.

Paxton, 33, and her daughter Sammi, 11, work their block of a gated community, but they restrict their sales to people who know them. "They seem to be OK with Sammi but if all 15 in my troop dispersed?" She shakes her head. "Seriously, they would probably call security."

Although Gulfcoast Girl Scouts public relations director Kathy Carol emphasizes parents and children working together to sell cookies, cookie mom Cheryll Patterson says that parents are pivotal — particularly in pre-sales. Last year, in fact, she bought about a third of the 180 boxes so her daughter Tanesha could get the "Cookie Diva" pin. In the end, Tanesha and her mom sold more than 600 boxes.

Ten-year-old Mariah Rodgers, a member of Paxton's troop, says she just likes selling cookies. She doesn't care about the prize. "My mom sold at both of her jobs," she adds. Her mother is a waitress. They've sold 238 boxes so far.

"I have great parents," Paxton says. "If you have lousy parents, you are going to have lousy cookie sales."

If parents' sales are so vital, what is selling cookies about?

"You mean, what do we want it to be about or what do the girls think it's about?" Paxton asks.

For her, it's a lesson in responsibility that comes while doing something fun. For the girls — well, it's mainly about the prizes, the projects and the trip.

Most of Troop 2083 sit on the edge of the stage in the cafeteria of Calusa Elementary where they meet every other Thursday night. They listen to Patterson outline this year's possible destinations, including a water park in Cape Coral and swimming with dolphins at Marathon.

A girl with dark hair raises her hand. "Could we go to France?" she asks.

"We could go to France if we want," says Patterson, "but we better start selling cookies and, probably, we'd not go until you are seniors."

"And you'd have to wear your uniforms on the plane," Paxton adds.

The girl raises her hand again. "Could we go to Ohio?"

Espie secrets of success

• Nothing keeps you from selling. Not rain. Not cold. Not the Super Bowl. Not husbands who don't get it. Not anything but home-schooling, daily ballet lessons, working and, of course, Girl Scout rules.

• Pack the car with cookies because if you take them everywhere, you sell them everywhere.

• Houses with lots of cars parked out in front are tempting, but it's not usually cost-efficient: Most of the drivers don't live there, which means you'll likely drive too far to deliver too few.

• One box of cookies isn't really worth your time after you figure in making the stop, picking up the cookies, delivery and dealing with the money. (Last year, Espie handled about $20,000, too much of it in dollar bills.)

• If a customer doesn't buy this year, they won't get a visit next year — although they may try again in two years.

• Go back to every house at least three times if no one's home and if they've bought from you the previous year. They'll return five or six times — and call — if a customer has bought eight or more boxes and made it on the best customer list.

• "My wife's not here" is not a "No." "We're not done with them until we're done with them," Diana says.

Next house

"When are we eating dinner?" asks Sierra, who's slumped in the back seat and staring out the window. She hasn't been able to ride her kick scooter much this afternoon because of all the gravel driveways. And her rollerblades didn't even make it into the van: too many puddles.

"After dark," Diana replies, looking at Sierra in the rearview mirror. She turns to me. "We go and go and go until we drop. I'm always, always fighting the clock, how starving she is, trying to get away from work."

They've had doors slammed in their faces. Diana spends many nights during cookie season juggling the logistics of it all, sometimes until 1 in the morning. She incessantly makes lists, referring to last year's for their stops this year, and transferring names of actual buyers to a new list in a sort of childlike scrawl. They insulated the two-car garage with special foam to keep out the bugs and keep in the cool the wall-to-wall boxes of cookies require. They think, talk and just about dream Girl Scout cookies. For a few months anyway.

"Now what do you do when a dog approaches?" Diana asks. Sierra knows, but her mother seems to like the Socratic method of teaching.

"Stand still," Sierra intones as she gets out, her order sheet and lucky pen in her left hand. Elfin like her mother, she takes tiny steps towards the driveway, which is at the end of the road. As if to prove some cosmic point, two large, black dogs suddenly appear from nowhere, digging their way down the driveway in a full-out run.

Then everything collides into the same moment in time: The dogs slidingslidingsliding through dirt and gravel as they put on the brakes; Sierra's strange stillness; Diana's shout and fast walk to her youngest daughter.

Up close and at slower speeds, Diana recognizes the dogs. They were puppies last year, she says, looking down at flapping tails with Labs attached.

Sierra resumes walking toward the house with Diana, notebook pressed to her chest and pulling up the rear. One of the dogs waits at the top of the path with a shoe shoved vertically in its mouth, any menace erased by the cartoon gesture.

"Look at all they've done to the house, Sierra," Diana comments as they reach the door.

Together Diana and Sierra — maybe all longtime Girl Scouts — remember what the perpetual stream of newcomers don't know to forget. The trampoline that just disappeared one year; the lady on the corner who once had a million-dollar road to herself; the treehouse forsaken by children all grown up; the trained monkey; and of course, the dogs.

There's been one bad bite, early on, when Diana wasn't as savvy about dog psychology. A big dog on Husky Lane sent Arielle to the emergency room.

The story, the bites, the moments when you don't know what's going to happen don't phase Sierra. Sierra likes the dogs.

Not a good day

By 6 p.m., the honeyed light of late day has drained away to not-quite dark, and a cold wind gains strength, sending a trio of melaleuca trees into a hula shimmy. The churning dry bark mews, inexplicably, like a lost cat.

Sierra waits at an open door as the sound of cartoons filter out to her. She peers past the screen, past a woman in an actual apron and into warmth of dinner on the way to the table.

"Would you like to buy some Girl Scout cookies?" she asks the woman, who points amiably down the path to a man, one of Sierra's favorite buyers. In their 58 stops today, Sierra makes her pitch quickly, quietly and much the same way, using the business end of her lucky pen to focus your attention on the cookie she's describing. A marketing director couldn't do it much better.

Steve Ritrosky, who has joined them on the stoop, takes the order sheet from Sierra.

"OK, how many should I buy?"

Sierra twists fetchingly in the way only a 10-year-old can. Finally, she shrugs. She wants to pet his horse, which observes from a nearby paddock.

"Hmmmm?" he prods as he skims the descriptions.

"You should get seven."

"Seven? That's more than anyone else."

"But that's our fourth sheet," interjects Diana, who stands just far enough away to suggest Sierra's independence.

He buys seven.

As Diana pulls into their garage, which in a week will be filled with cookies, she already knows today's total.

"Fifty boxes in exactly four hours." Which is eight hours if you count delivery.

Fifty boxes is good? "Well, not good. Average. But you can sell 100 boxes in two hours at a booth."

The two wander into the kitchen of the immaculate home. Everest, the family Yorkie, barks from the lanai.

Diana seems nervous now. She answers questions willingly, but I've interrupted her focus today and it's after seven and she still has to work on the curriculum for the next troop meeting.

I leave, but later I call back. Why, I ask finally, do you do all of it?

Silence.

"Why," she says as if I'd asked by she chose to breathe. I can hear plastic bags ruffling in the background as she readies materials for a booth sale today.

"Ohhh, well, you saw what it was like," she says. She ticks off her motivations. "It's fun to do something with kids. It's fun to see the people. It's important money for the troop. It's just ... I don't know, Sierra and I enjoy our time together."

"And, oh," I say before letting her go, "Sierra's goal is still 3,000 boxes?"

"Well, I don't think we're going to make that." She calls to Sierra somewhere in the house. Do you want to adjust that goal, she asks her. "Well, we may be adjusting it. 'Cause reality sets in."

She laughs.