Half-brothers Paul Hannan and Richard Emery met for the first time in early March at Hannan’s house in Connecticut, but even after 51 years living as strangers, Emery said he felt like he was home.

“It felt complete,” he said. “It was opening a new chapter of a book.”

The brothers used DNA matching website MyHeritage to find each other.

Their mother, divorced from Hannan’s father and whose boyfriend was Emery’s father, gave up Emery for adoption when she was 30 years old.

Emery grew up happy with his adopted family and said he didn’t want to start looking for his birth mother until after his adopted parents were older out of respect for their feelings. He spent several hundred dollars a few years ago making inquiries with his adoption agency on his biological family. But by the time the agency reached out to her, his biological mother had suffered a stroke, and Emery was told she said it wasn’t a good time.

“She gets this letter in the mail from the adoption agency, can you imagine, 50, 51 years later?” Emery said. “She had whatever reasons, whether it was health reasons, or emotional reasons, she had her reasons.”

“We both regret that we couldn’t have had that opportunity with our mother,” Hannan said. Their mother died in January.

Hannan knew all along he had a sibling – and was seven-years-old when his mother gave Emery up for adoption – but the family never talked about it because Hannan thought the subject might be too painful for her.

In November, Emery watched a documentary on DNA testing.

“The older I’ve gotten, in watching programs on adoption and things of that nature, it would touch me,” he said. “It would, sort of, touch my heart. And then I would wonder.”

He ordered a DNA kit from MyHeritage and a few weeks later got a match to a first cousin. After he contacted her, she contacted Hannan and the rest is history, or a “new beginning,” as Emery calls it.

While Hannan calls their later-in-life meeting “the happy ending”, bioethicist Arthur Caplan told Reuters there are downsides, like privacy issues or the fear of reselling DNA information, that could deter customers from using companies like MyHeritage.

“Many people put children up for adoption and they don’t want to be found as the mother, the biological mother, they’re embarrassed or they’re humiliated, they moved on,” said Caplan, director of medical ethics at New York University School of Medicine. “They (the companies) promise not to resell it with your name attached, but more and more it’s getting easier to figure out who you are from your DNA. If I have a few other medical records or I know your zip code, there are ways I can start to infer whose DNA it is. So I don’t think you can be assured 100 percent privacy, and in an era where everybody is hacking into databases, forget it. You just have to be ready to understand you might lose your privacy.”

Family history author Yvette Corporon, who started collaborating with MyHeritage after successfully finding a family her grandmother hid from the Nazis during World War II, said the company keeps DNA information completely private.

“You own it, it is only for your use, your purposes,” she said. “Again they do not share it with anyone and you can delete it at any time from their database. Also, you can remain anonymous. You can use a pseudonym, you can use your initials. You don’t have to put your name out there for anyone to look at and it’s up to you on whether or not you delete your information or whether or not you choose to actually reach out to people whose DNA matches with yours. So basically they’re putting everything in your hands.”

According to MyHeritage, revenue from DNA sales last year was $58 million (USD), with an overall company profit of $18.1 million. The company was founded in 2003.

Caplan said he thinks the reason DNA testing companies do well is because they capitalize on the idea “you are your genes”. But he credits environment, upbringing and schooling as equally important to a person as his “genetic messages”.

MyHeritage’s latest project is DNA Quest, which aims to reunite adoptees with their biological families. The company is giving out 15,000 DNA kits worth more than $1 million for free for eligible applicants through an application on www.dnaquest.org.