"I'm happy they want to help. There are a lot of people who can't afford to buy these tickets on their own," he said.
Shankman, a New York City entrepreneur, podcast host and single father who travels the world to deliver corporate keynote speeches, decided to start giving away his frequent flier miles when he realized how many he wasn't using every year.
"The moon is almost 250,000 miles away, and I travel more than that annually," he said, adding that he went to Asia 11 times this year, among many other trips.
After giving miles to his parents and his office assistant every year, Shankman is still left with several hundred thousand extra miles.
One winner of his contest this year is Sarah Latham, 33, who had been weighing a painful dilemma: Her grandfather is dying from cancer and lives 1,593 miles from her home in Texas. She knew that if she flew to New York to see him at Christmas, her family would go into debt to pay for the flight. If she skipped it, she might never see him again.
"He's had a long, hard fight, and it's the last opportunity I'd have to see him," Latham said.
Then, her husband entered her into Shankman's contest. With several thousand votes from Imgur users, she became one of five winners.
"I'm happy I won because now I have the opportunity for one last memory," she said. "After my dad died, the relationship I have with my grandfather became even more important than I have words to describe. This is my trip to say goodbye. "
Donated miles also will be used to fly a couple from Los Angeles to be with their family of 30 in Utah for Christmas, and send brothers who live in San Diego and North Carolina to share the holidays with their mother for the first time in years.
Shankman will also send a woman with Parkinson's disease to Georgia with her son to place flowers on another son's grave, 11 years after his death. And he'll fly a man from Kansas to New Hampshire for a surprise holiday visit with his mother, who had her second heart attack, and his father, who is fighting skin cancer.
The first year Shankman started his contest, in 2014, he had an assistant select two people from hundreds of applicants who had submitted heart-wrenching stories on his website. A year later, he decided to switch his contest to Imgur, an online image-sharing community, "because it was just too difficult to choose the winners ourselves."
Thousands of people voted for the winners.
Other frequent fliers have been donating their miles to his cause. "It makes me happy to know that others who fly a lot also want to help," said Shankman, 46.
One of those donors is Rhys Ford, a mystery writer from San Diego who travels thousands of miles every year to attend conventions and book-signing events.
Ford says her reason for donating her extra miles to Shankman's "Home for the Holidays" giveaway is simple and heartfelt.
"There are many of us who have so much, and there are others who are far away from their family and can't make it back for financial reasons," she said.
Shankman, who shares custody of his 5-year-old daughter, Jessica, with his ex-wife, said one of the big pluses of giving away his miles is that it allows him to pass along a lesson about giving.
"It helps show the importance of family," he said.
Shankman grew up as an only child in New York City with parents who were both schoolteachers.
"We weren't rich, but we never struggled," he said. "I always felt the warmth of family."
Diagnosed with attention deficit and hyperactivity disorder in his mid-30s, he decided to channel his energy and impulsiveness into business and learned to look at it as a gift.
"I have massive ADHD, but I believe it's a huge part of my success," said Shankman, who published a book last year (his fifth) chronicling his journey, "Faster Than Normal: Turbocharge Your Focus, Productivity and Success With the Secrets of the ADHD Brain."
He said his life changed when he realized his different brain could be a benefit.
"I can hyper-focus for long periods of time if I set myself up for it, and I can use my 'faster than normal' brain to launch companies and start to bring in revenue in the time it would take a 'normal' person to sketch out an idea," he said.
Shankman's goal, he said, is to help children and adults with ADHD realize that they're not broken, but gifted.
"They just need to learn how to channel and use that power," he said.
Part of what keeps him going, he said, is giving back.
"People ask me how I verify the stories of people who win the free miles," Shankman said. "And I tell them, 'I can't.' But if someone goes to all this trouble to get a free trip somewhere, maybe this will help them in some way. As long as my miles keep adding up, I'm going to continue to give them away."
