How the world shares its secrets Frank Warren started a website that collects secrets mailed to him on postcards He says the site is the most popular ad-free blog When secrets are shared publicly, they can help unite people, he says. Warren: The site has received half a million secrets since its founding in 2007 Editor's note: Frank Warren is the founder of PostSecret www.postsecret.com He spoke at the TED2012 conference last month. TED is a nonprofit organization dedicaated to "Ideas worth spreading," which it makes available through talks posted on its website (CNN) -- I like to watch Dr. Phil drunk. Dear Birthmother- I have great parents, I've found love, I'm happy. Everyone who knew me before 9/11 believes I'm dead. Hundreds of secrets like these arrive in my mailbox every week. They come anonymously on artful postcards from all over the world. In seven years I have received more than a half-million. I give decaf to customers who are rude to me. [written and mailed on a Starbuck cup] To the class of 1977, I still hate you all. I leave poetry behind in library books. Watch Frank Warren's TED Talk When I started PostSecret as an art project in 2007, I had no idea that this simple project would turn my life upside-down and offer such a fascinating peek into the rich hidden world that we share but don't talk about. I printed up 3,000 self-addressed postcards inviting strangers to share an artful secret on a postcard -- something they had never told anyone before -- and mail it to me anonymously. When they started arriving I began scanning them and posting them on the web. The idea began spreading virally with people buying and making their own postcards. Today www.postsecret.com is the most visited advertisement-free blog in the world with more than 500 million hits. Most fascinating to me are the stories behind the secrets or the intimate connections that can happen between people when they share secrets. TED.com: The web's secret stories When I posted a secret from someone who confesses to thinking about jumping from the Golden Gate Bridge, PostSecret Blog readers sprang to action creating a Facebook group page called, Please Don't Jump. They posted encouraging pictures and shared their own inspiring stories of hope. 60,000 people joined the group in 10 days. The next week the San Francisco City Council proclaimed the first annual "Please Don't Jump Day." Shortly after that the PostSecret community created the most comprehensive directory of suicide prevention hotlines in the world. Sharing Secrets can be transformative and this project has changed my life. I learned early on that there are two kinds of secrets; the ones we keep from others and the ones we hide from ourselves. This project has helped me uncover secrets from my past that were haunting me. I have written my secrets on postcards, mailed them to myself, and spoken to my family about them for the first time. I have one of my secrets in every PostSecret book. The most exciting part of the project for me today is traveling to universities and sharing secrets live. At these PostSecret Events I not only show the most extraordinary secrets in my collection, I also try to create a safe, nonjudgmental social space where students feel comfortable expressing their private secrets publicly. TED.com: The happy secret to better work Seeing young people courageously share their vulnerabilities can be highly emotional and meaningful. It reveals a secret about the nature of our secrets: They can be walls that separate us or bridges that unite us depending on the choices we make and the actions we take. At one PostSecret Event at a large conference in Austin, Texas, called South by Southwest a surprising thing happened. In front of an audience of more than 2,000 people a young man stood and proposed marriage to his girlfriend -- to the delight of the audience. Someone there recorded that special moment on a cell phone and it has been watched over 300,000 times on YouTube. Perhaps my favorite secret out of the hundreds of thousands I have received was mailed to me on a dollar bill. I carry it in my wallet all the time. It reads: We are all part of something bigger, and we are all part of it together. Follow us on Twitter/CNNOpinion The opinions expressed in this commentary are solely those of Frank Warren.