PHILADELPHIA -- Philadelphia is well known for many things, but this isn't necessarily one of them: It's home of the Girl Scout cookie.

The Philadelphia Gas Works used to hold cooking demonstrations at Broad and Arch streets, where it had window displays of shiny new gas ranges. In 1932, Girl Scouts, working for their cooking badges, baked cookies in the display ovens and handed them out to passers-by on the street. When one of them offered to pay for a cookie, an idea was born.

The next year, the scouts baked cookies and sold them to pay off the mortgage for Camp Indian Run at Glenmoore in suburban Chester County. Girl Scout cookies went commercial in 1934 when the Philadelphia scouts hired the Keebler Baking Co. to bake trefoil-shaped shortbread cookies, which they sold for 23 cents a box.

The project was such a hit that in 1936 Girl Scout cookies went national, and today the the Girl Scouts of America are the nation's fifth-largest cookie retailer, according to the organization. They sell nearly 100 million boxes a year, or about 15 cookies for every man, woman and child in America. So good are they at selling cookies that management expert Peter Drucker once told The New York Times that he thought the Girl Scouts were the best-managed organization he'd ever seen.

The annual sale began yesterday. To observe this 55th anniversary, we thought we'd tell you everything you wanted to know about Girl Scout cookies -- and some you never thought to ask:

How much do Girl Scout cookies cost?

They're $2 a box in Philadelphia, which is 30 to 40 percent higher than most comparable store-bought varieties, but the price varies nationally. The number in a box varies from 15 to 42.

Why are people willing to pay so much more?

Pat Dyer, marketing director for the Girl Scouts of Greater Philadelphia, says the reason is that "people want to buy Girl Scout cookies."

But it's also smart marketing.

The Girl Scouts have a highly motivated sales force of children and volunteers (only 1 percent of the organization is paid staff). At "cookie rallies" preceding the annual four-week sales campaign, the girls learn to establish eye contact with customers, remember customers' names and set personal sales goals. Small gifts, such as T-shirts, for supersellers provide incentives. Dyer also distributes sales training videos and gives out hand puppets so the scouts can act out selling situations.

Who makes Girl Scout cookies?

The Girl Scouts license three bakeries nationally. Each local council then picks one of the three. In the competition for these lucrative contracts, bakeries try to outbid one another in price, advertising services, speed of delivery and free samples.

Who sells Girl Scout cookies?

Four classifications of Girl Scouts: Brownies, who are 6 to 9 years old; Juniors, 10 to 12; Cadettes, 12 to 14, and Seniors, 14 to 17. Five-year-old Daisies are not permitted to sell cookies. Many of them don't know how to make change.

Where can I buy Girl Scout cookies?

Because so few women are home during the day anymore, door-to-door selling is giving way to cookie booths in shopping malls, in the lobbies of public buildings and on college campuses, where, for many homesick students, Girl Scout cookies are the next best thing to Mom's brownies. Some Girl Scouts use telemarketing techniques, such as phoning the neighbors for orders. If you can't find a Girl Scout, call your local Girl Scout Council.

What kinds of Girl Scout cookies are there?

The three traditional Girl Scout varieties that all three licensed bakeries must offer are the trefoil shortbread cookies, Thin Mints and Do-Si-Dos, peanut butter-oatmeal sandwich cookies. The bakeries can add selections such as Tagalongs, chocolate-covered peanut-butter patties; Chocolate Chunks, chocolate-chip cookies; Samoas, caramel-covered cookies; and Echos, chocolate-sandwich cookies.

What's the most popular kind?

Thin Mints -- which are chocolate-coated, peppermint-flavored chocolate cookies. They account for 25 percent of sales nationwide.

Marketing studies have shown that people's tastes vary from region to region. Because chocolate is quite popular on the East Coast, the chocolate-sandwich cookie returns this year. The Girl Scouts have also found that consumers prefer crunchy chocolate chip cookies to chewy ones.

How many calories in a Girl Scout cookie?

The least fattening cookies are the shortbreads, at 33 calories each. No one's saying what the calorie count is on the super-rich Samoas, made with caramel, coconut and chocolate.

Are Girl Scout cookies nutritious?

Well, they contain no preservatives or artificial colors. Girl Scout cookies aren't meant to be a health food, though, and several years ago, when some councils tried selling a granola cookie, it bombed.

Still, last year an Idaho couple stranded in their car in a snowstorm for 13 days survived on nothing but soft drinks and two boxes of Girl Scout cookies.

Where does all the money go?

Sixty percent of the proceeds of the cookies goes to the individual troops and to the councils to support Girl Scout camps and program activities. A small percentage (3.5 percent) goes to the cost of the sale, and the remaining 36.5 percent pays for the cookies.

Troops get 35 cents for each box of cookies they sell and a two-cent bonus per box if a council meets its sales goal.

What is a "cookie mom"?

A cookie mom volunteers to take charge of cookies for each troop. The cookie mom picks up the cookies from the "cookie depot" and then stores the boxes, parcels them out to the scouts and accounts for the money. Cookie moms are the linchpins of the whole sales operation, and a troop that can't recruit a cookie mom doesn't sell cookies.

Occasionally, cookie moms are fathers.

Why are cookie sales held in the winter?

The Girl Scouts deny that they're trying to enlist people's sympathy for cute little Brownies shivering in the cold. They say the reason is that the troops like to earn money for spring and summer activities, such as camping and horseback riding. Furthermore, the chocolate coatings don't melt in cold weather.

Girl Scouts in some parts of the country sell cookies at other times of the year.

Does anybody not like Girl Scout cookies?

Yes, some Girl Scout leaders. Cookie sales, they say, place demands on time that could be spent on community service, earning badges or even just singing favorite Girl Scout songs. "We work so hard selling cookies," laments Frieda Johnson, 80, a volunteer who has sold Girl Scout cookies for her daughter's troop and her two granddaughters' troops and for the last several years for a Cadette troop in her Germantown neighborhood in Philadelphia. "The Boy Scouts don't have to sell cookies to support themselves."

This, of course, is true. Nobody said life was fair. Generations of former Boy Scouts who hold important positions in business contribute to scouting and arrange for corporate support. Very recently, the Girl Scouts have begun to tap into the emerging "old girl network," but still, cookie sales account for half of most Girl Scout Council budgets. (The rest comes from camp fees, equipment sales, investments, individual and corporate donations and United Way contributions.)

"Without cookie sales," says Executive Director Judith Borie, "we simply would not exist."