LAS VEGAS — It's like the world's biggest beach party, hosted by the world's richest beach bum.

Singer Jimmy Buffett's popularity and fortune grow greater even as his hair grows grayer.

His final concert of the season was sold out to 15,000 fans at the MGM Grand arena in Las Vegas.

Buffett, who turned 62 on Christmas Day, long ago became an icon of baby boomers by offering the dream of throwing off their responsibilities for his tropical party vibe.

But in the past decade, this chronicler of Margaritaville has really cashed in on his image.

How big is Buffett?

With an estimated annual income of more than $40 million, you might mistake his portfolio for that of Warren Buffett (not a relative). And he's done it by sailing beyond most musicians' ticket, T-shirt and poster revenue stream.

The title of his most popular song shows up on restaurants, clothing, booze and casinos. Among the products he's involved with are Landshark Lager, the Margaritaville and Cheeseburger in Paradise restaurant chains, clothing and footwear, household items and drink blenders. The Margaritaville cafe on the Las Vegas strip is said to be the top grossing restaurant in the nation.

Buffett writes best-selling novels. There's Radio Margaritaville on Sirius. His recording career is booming even as the music industry tanks: His recent album, "License to Chill," was the first No. 1 album of his career.

In October, Buffett was ranked by Vanity Fair as No. 97 on a list of the 100 most influential people. In the world. He's nestled between Universal Music Group CEO Doug Morris and anti-poverty crusader Jeffrey Sachs.

But the exact scope of the Parrot Head empire is secret. Buffett's privately held Margaritaville Holdings LLC does not disclose its finances, and his publicists declined numerous requests for interviews with the singer or anyone connected with Miami-based Margaritaville Holdings.

"He wants to be known as an artist and musician, but he's an extremely savvy businessman," said Brian Hiatt, an associate editor at Rolling Stone who covers the concert industry.

Buffett's fan base is broad, and is not tied solely to a string of past hit songs. For most of his career, Buffett had only one Billboard Top 10 hit, "Margaritaville," in 1977.

What he offers his fans is an accessible fantasy.

"Anyone of any age could imagine retiring to a tropical paradise and drinking margaritas," Haitt said. "There is something extra-musical about the whole thing."

Margaritaville boat shoes and flip-flops are found in shopping malls. Margaritaville Foods sells salsa, hummus, tortillas and dips in Wal-Mart and other stores. Landshark is sold in grocery stores, and Margaritaville tequila is in liquor stores.

And concert tickets sell out in short order, despite prices that run well over $100. The Buffett brand is on a growth spurt, usually as a result of marketing deals.

The Cheeseburger in Paradise chain was founded in 2002 and is owned by OSI Restaurant Partners, owners of Outback Steakhouse, under a license from Buffett. Landshark Lager, made by Anheuser-Busch, and Margaritaville Tequila, made by Seagram, are sponsors of his concerts.

Last May, the Trump Marina Hotel Casino in Atlantic City was purchased by Coastal Marina LLC, which will convert it into a destination resort under the Margaritaville label.

"Jimmy Buffett and his team at Margaritaville have created an extraordinary brand that is instantly recognizable to an enormously large and dedicated fan base," said Richard Fields, CEO of Coastal Development. "The brand implies quality, value and good times."

Meanwhile, Harrah's Entertainment Inc. has teamed with Buffett to develop the $700 million Margaritaville Casino & Resort in Biloxi, Miss., near where Buffett was raised. That project has been delayed by the economic downturn. But Harrah's and Buffett already have a profitable relationship. According to Buffett's Web site, the first Margaritaville opened in Key West, Fla., in 1987. The chain has since grown to 16 outlets, including a new one at the Mohegan Sun casino in Connecticut.

Margaritaville at the Flamingo Las Vegas takes in more than $43 million a year, said casino president Don Marrandino.

"It's been pretty consistent for five years," Marrandino said. "It speaks to the Buffett lifestyle."