The organization and registration of the race is handled by the city's Department of Parks and Recreation. But the race's main sponsor is Independence Blue Cross.
"We were overwhelmed with a response that was beyond wildest expectations," said Judimarie Thomas, spokeswoman for Independence Blue Cross.
She said the company was sorry some runners experienced frustration during the registration, but was "thrilled" at the level of enthusiasm for the event.
Because of demand, the Parks and Recreation Department informed runners that a lottery would be held to open an additional 2,500 spots. The link will be posted on www.BroadstreetRun.com tonight. Runners can enter the lottery between now and February 24th.
The 33rd annual run, billed as the largest 10-miler in the country, is scheduled for 8:30 a.m., Sunday May 6.
Jamie Faussett, 25, of New York City, is a relatively new runner and the Broad Street Run, recommended by friends, was to be her first race.
So she went to the website for the race at 9:50 a.m. - 10 minutes before registration started - and her troubles began almost immediately.
"I'm actually not even 100 percent positive that I've been registered," Faussett said. She entered all her information and waited almost an hour for her information to process until she received a message that the website was unavailable.
"I was freaking out," Faussett said. Then, she called a number on the website and someone took her information. She's awaiting an email confirmation.
Faussett said she was told 13,000 people had already registered at that point - and the registration had only been open for two hours.
"That's insane," she noted of the demand. "So while it's frustrating that the process took two hours, you can't fault them. People want to run this race."
One disappointed registrant said he was, "very frustrated" and expects to see tickets for sale on Craigslist or elsewhere.
Dr. Jeremy Jordan, director of the Sport Industry Research Center at Temple University, says the race course's longevity, downhill slope, and enthusiasm of participants all play a role in the Broad Street Run's popularity.
"The timing allows for participants to set a spring goal for running that significant, yet manageable 10 miles," Jordan said in an email. "It's a nice way to come out of the winter."
The Sport Industry Research Center at Temple has researched participant satisfaction in the race.
Last year, 94 percent of participants said they would be likely to recommend the event to others, and 87 percent said they were likely to run the race this year, according to Jordan.
It also attracts more than half its runners from outside the Philadelphia region.
But a word of advice for those still hoping to register: make sure you're in decent shape. Runners falling below a 15-minute-per-mile pace face getting yanked.
And if you think that's fast, top runners average well-under five minutes per mile. Last year's winner, Ketema Nigusse, 30, of Ethiopia, ran the course in 46:29.
(Note: The Philadelphia Daily News is also a sponsor of the event; see our Broad Street Run coverage.)
Contact Frank Kummer at firstname.lastname@example.org