George Michael, left, at Ahoy, Rotterdam, Netherlands, April 12, 1988. Dan Gore, right, has been a professional George Michael impersonator since the age of 20.

When Dan Gore was in high school in the 1980s, people kept telling him he looked like George Michael, one-half of the then-popular British pop duo "Wham!"

By the time Gore was 20, George Michael had established himself as a solo artist. Gore, meanwhile, had established his career too: as a George Michael lookalike. He traveled the world as a George Michael impersonator, lip-synching Michael's songs in stage shows and even once appearing on "The Tonight Show with Jay Leno" in a skit lampooning the performer.

Today Gore, 44, runs Icons, a talent agency representing hundreds of lookalikes and has also produced stage shows featuring impersonators. One of the more famous lookalikes on his roster is Jeff Barnett, a former stockbroker who bears an uncanny resemblance to Charlie Sheen. Other lookalikes he represents include those impersonating music icons Madonna and Michael Jackson to reality TV staples Kim Kardashian and Paris Hilton.

"People want a touch of Hollywood," Gore said, explaining lookalike's allure.

Gore's lookalikes do everything from appearances at trade shows to serving as stand-ins for the real stars when movie and music video directors need to test lighting set-ups. Annual income for celebrity impersonators can range from some $15,000 to more than $100,000, though Gore is quick to add that it's usually only political impersonators - especially President Obama look alikes - who rake in top dollar.

When a celebrity's popularity wanes, so do the fortunes of their impersonators. Gore himself hasn't done a George Michael appearance in a year.

"Once they're not as popular in the public's eye, then you're not as popular either," he said.

Gore's number one tip to impersonators? "Don't quit your day job."

Take an inside look at the lives of celebrity impersonators on "20/20? Friday at 10 p.m. ET.