FYI: Does the emergence of a sex tape help or hinder a celebrity's career?

Sex sells, as the saying goes - or does it? The pool of illicit videos featuring the rich and famous in assorted compromising positions seems to expand each week, and the celebrity-sex tape is now a global phenomenon.

Among the more recent scandals garnering widespread attention is one involving Vietnamese television actress Hoang Thuy Linh, a virtual unknown outside her native land before a five-minute clip of the young woman getting intimate with her boyfriend surfaced on the internet. A lot more people have heard of her now, but it would be hard to argue the romp improved Hoang's job prospects. Vietnam remains a conservative place and pressure from indignant parents has forced the state broadcaster to pull the plug on the teenage soap opera that had defined her career.

Some sex-tape stories in other countries have more beneficial endings. In fact, there's a pretty visible connection in Hollywood between unsanctioned pornography and a rise in celebrity fortunes.

One obvious example is socialite Paris Hilton, who, thanks to the timely leak of a raunchy videotape just a week before her TV debut in reality show The Simple Life, saw the first couple of episodes attract a much higher than anticipated 13 million viewers. Whether the leak was deliberate or not remains unknown, but there must be a reason Hilton biographer Chas Newkey-Burden has called her a 'business genius'.

Pamela Anderson had only a supporting role in Baywatch, but in 1998, not long after a clip of her frolicking on a yacht with then-husband Tommy Lee was widely distributed, she was made the star of her own show - VIP, a comedy-drama that cast her as a bodyguard/private detective.

Titillating recordings are now seen as such an effective catapult to notoriety that D-list celebrities are practically queuing up to release them. In 2004, American professional wrestlers Joan Laurer, better known as Chyna, and Sean Waltman, or X-Pac, convinced an adult-film-industry heavyweight to market a homemade video of one of their trysts. While the pair haven't exactly become the toast of Tinseltown, the stunt did at least earn Laurer a place on The Surreal Life, a long-running series on music channel VH1.