TV reality star Kim Kardashian has finally achieved the fame she seems to have been searching for all her life. At last she has a world record to her credit, set during her wedding to basketball star Kris Humphries.

Unfortunately, the record had nothing to do with the lavish ceremony in California, her Vera Wang wedding gown or even her honeymoon. No, the world mark was set for nothing other than sex-tape sales.

Can you believe it? I thought sex tapes were old hat by now. However, paid access to the website showing Kim having sex with R&B singer Ray J is still doing a roaring trade and hit a peak during the weekend of her wedding. No fewer than two million people visited the site, making her tape the most popular the world has seen.

That is amazing, seeing the video has been around since 2007. Four years later, it is still drawing around 300000 visitors a month.

Access to the site is around $4 for three days and $27 for a month. You do the maths - this shoddy video puts some Hollywood movies to shame when it comes to income.

However, signs are that Kim, 30, may have grown a little tired of having her naked body flogged on the net. Now that she is a celebrity, she probably doesn't appreciate that nasty little reminder of the days when she was scrambling to get noticed. Unfortunately for her, she sold off her rights to Vivid Entertainment for $5-million. All she can do now is try to buy it back.

This week Vivid Entertainment boss Steve Hirsch said a price of $30-million was a starting point for getting the tape taken off the market. He confirmed he had been contacted by a lawyer representing a mystery buyer who wanted the rights to the video. Coming just after her wedding and upsurge in interest, it would not be a big surprise if Kim were behind the approach.

She would probably be delighted to surrender her viewership record to actress Kendra Wilkinson, who features in the second-most-viewed sex tape of all time. The blonde reality star is a former girlfriend of Hugh Hefner and resident of the Playboy mansion. Her tape was made in 2005 by her then boyfriend, who set up a camera and stripper pole in his bedroom. At first, Kendra sued for the rights to the tape, but later agreed to sign them over to Vivid. As part of a lucrative agreement, she gets 50% of the sales generated by the tape. A few years on, she's still raking in the bucks.

You may be wondering why Kim's and Kendra's sex tapes are doing all the business and not those featuring a more famous star like Pamela Anderson. The difference, I have learnt, is that Anderson and other famous celebrities did not agree to the screening of the videos. So, while they are shown illegally on some internet sites, no one is entitled to charge for access to them or make money off them without inviting legal action.

I am not sure we realise just how much part of our culture the sex tape has become. Actor Rob Lowe became a pariah in Hollywood in the 1980s when he made a video of himself having sex with two women, one a minor. But today some wannabe stars see a saucy tape as a way of gaining publicity. And tapes are also regularly used as a weapon in love quarrels or divorces involving some of the world's most famous people.

Paris Hilton's sex tape is one of the most famous and almost certainly made her famous.

British TV star Ulrika Jonsson took legal action to stop footballer Stan Collymore from selling an explicit video of the pair having sex, while actor Colin Farrell got a court order blocking the distribution of a 13-minute sex tape.

Politicians have also felt the brunt. In 2008, the Malaysian health minister, Chua Soi Lek, had to quit after a tape showing him having sex was made public. And, in 2010, US presidential candidate John Edwards was shamed when a sex tape surfaced of him having sex with his mistress, Rielle Hunter. She was allegedly pregnant with his love child at the time.

These days, making a sex tape is almost child's play. With digital technology, filming at home is as simple as turning on a cellphone. You don't need to store the images on a clunky old tape either. You can upload your X-rated images onto digital platforms where they can be hidden or distributed.

Unfortunately, they can also be stolen or hacked, as Limp Bizkit frontman Fred Durst discovered. A video of him having sex was leaked by a repairman who had been fixing his computer.

I've said this before and I will say it again: why do these people film themselves having sex? It baffles me no end. Maybe I am just an old-fashioned country girl, but I will make sure that no one brings their fancy digital camera or cellphone into my bedroom. I have absolutely no intention of raining on Kim's parade.