What is the first thing you associate with Oprah when you hear her name? Maybe the first thing is philanthropy or charity work. This is because Oprah and her team have developed and defined her personal brand over the years, including donating millions to fund scholarships for children’s education and helping poverty-stricken children in South Africa. Developing a personal brand can be tricky and is certainly a lot of work.

So how do you define a personal brand? One of my favorite definitions, brought to my attention by AKHIA President Ben Brugler earlier this year, is, “Personal brand is what people say about you when you leave the room.” Jeff Bezos from Amazon.com said this, and it resonates. You can do all you want to make your image and online presence look precisely how you want, but if you don’t follow through, it’s all for nothing.

Many celebrities developed their own brand as they’ve risen to fame. I’ve highlighted some of the strongest and a few personal favorites.

Kevin Hart: comical, straight-forward and surprising.

Love him or hate him, Hart has developed a very strong personal brand and recognizes that. I follow him on all social networks, and he truly calls it how he sees it. There’s nothing I dislike more than being able to tell when a publicist or manager is tweeting for a celebrity, and it’s clear there is no middle man managing Hart’s social accounts. My favorite part about Hart is, as he has become more successful over the years, he continues to recognize his fans who have made him successful. On multiple occasions he has bought out whole movie theaters, tweeting out for fans to race to the theater to get a free ticket as a token of his appreciation for their support. (Hart even did this with his most recent movie.)

Jimmy Fallon: quirky, unpredictable and innovative.

In addition to being the host of The Tonight Show, Fallon has been in the spotlight for some years now starring on Saturday Night Live in the late 90s. In lieu of rebranding The Tonight Show, NBC branded Fallon as one of the funniest, quirkiest guys in late-night television. It’s hard for a week to go by where a video from Fallon’s show doesn’t go viral on social media. From Lip Sync Battles to eccentric games played nightly with guests, Fallon has garnered a reputation for pushing the envelope with his guests and surprising his audience…in a good way.

Taylor Swift: fan-oriented, charitable and focused.

Perhaps the person with the most definitive personal brand in pop culture right now, Swift has made it clear she calls the shots, and her fans are her No. 1 priority. Sending Christmas gifts by the box load to them is one of the many things Swift has gone out of her way to do for fans in recent years. She has created an atmosphere on social channels where she openly engages with her fans’ everyday lives by giving them advice or simply making their day with a “like.” In addition, Swift is known for her charitable contributions to the community and the country music industry. She recently donated $4 million to the Country Music Hall of Fame to fund a music education center for children in the Nashville area.

What do you think best describes your personal brand?