BOSTON — After decades with the marathon world to itself, the Boston Athletic Association watched races in other cities begin offering prize money and appearance fees and flatter, easier courses that attracted the top talent.

The choice was clear for the world's oldest and most prestigious marathon: Accept the changing times, or become an also-ran in the running world.

Twenty-five years ago, the organizers of the Boston Marathon signed a sponsorship deal with John Hancock that for the first time provided prize money for the winners — and portable toilets for the masses — and acknowledged what runners had been saying for years: You can't eat prestige.

"It wasn't just the prize money," said Greg Meyer, whose victory in 1983 remains the last for an American man in Boston. "They didn't get you a hotel room. There were no Porta-Johns on the course. This was the old B.A.A. They thought, 'The marathon makes the athlete; the athlete doesn't make the marathon.'

"The partnership between the B.A.A. and Hancock has kept the race at a level that makes our victories meaningful. Without that, it would have been irrelevant. It would have been a regional race."

When Hancock signed on for the 1986 race, it was before stadium naming rights were the norm and before the Olympics welcomed the Dream Team of pro superstars at the Barcelona Games. Amateurism was still seen as the purest form of sport, and many within the B.A.A. thought that being a Boston Marathon champion — along with the traditional olive wreath and bowl of beef stew — should be prize enough.

"It was a different time and place back then. This turmoil about amateur vs. professionalism, it had been raging for many years," said Guy Morse, who was brought on by the B.A.A. to modernize race 25 years ago and is now its executive director. "It's hard to understand now, given the state of the sport."

But with the hemorrhaging of top competitors to more lucrative races such as London, which sprung up in 1981, the race's organizers realized that if they didn't change something, they might have little left to protect.

"It was a tough decision," Morse said. "We had standards and values that we wanted to preserve. They really wanted to protect all the traditions, and didn't want to negatively impact the race. It became apparent to the board at the time that you can offer prize money and maintain all the values that make Boston special."

Morse said the B.A.A. was not willing to sell naming rights — "It was not going to become the XYZ Company Boston Marathon," he said — and that weeded out some of the more corporate proposals. They soon found a kindred spirit in John Hancock, which is headquartered just blocks from the finish line.

"We definitely recognized the value of the tradition," Rob Friedman, the head of the company's sports marketing division, said this week as the sponsors and organizers alike prepared for Monday's 114th running of the race. "Boston was always sort of the Augusta of road racing."

From an initial prize of $39,000 each for the first-place man and woman — gender parity was another issue that was important to the B.A.A. — the winners' share has grown to $150,000 of a $806,000 purse; there is another $220,000 in potential performance bonuses for course, American or world records.

"Prize money made the Boston Marathon 100 times stronger," four-time winner Bill Rodgers said.

The sponsorship also opened other avenues, and not all of them corporate. A program that gives runners bib numbers in exchange for a commitment to raise money for charity, which started in 1989, is expected to surpass the $100 million mark for local causes this year; 1,350 runners from 24 charities are expected to take part in 2010.

The B.A.A. also began reimbursing the cities and towns along the route for their expenses, a program that has paid out $8.5 million over 25 years.

Hancock itself raised $3.7 million for its nonprofit bib program last year, Friedman said. The company also uses its involvement in the marathon as a promotional tool for its own salespeople, clients and customers.

And the field, which boasts two American contenders this year for the first time since the 1980s, is as strong as ever.

"Without the money, even the most prestigious of marathons fall back," said Mary Wittenberg, the director of the New York City Marathon. "The prestige and glamour of a win will always be big, but college kids today know that they'll be able to have a career in running.

"I think it was a visionary move here."