Trent Harmon will likely be known as the last American Idol winner, crowned last week, and for not much else in the music industry.

Despite being touted as a talent hunt for aspiring singers, American Idol has in 15 seasons produced only two music superstars worthy of being called idols - inaugural winner Kelly Clarkson, who has released seven albums and sold a total of 61 million records globally, and fourth-season champ Carrie Underwood, who has five albums and record sales in excess of 65 million worldwide.

Another two stars the show minted worldwide who became as big as, if not bigger than, Clarkson and Underwood are judge Simon Cowell and host Ryan Seacrest, who acknowledged as much when he said of the show: "I can't even begin to compare my life then and now. I mean, when this all started, I was living in a one-bedroom apartment and splitting the rent with another dude."

Sure, American Idol has made a mark in the entertainment world as a show that popularises the television singing contest with a "reality" element.

It is more about entertaining audiences and creating personalities who thrive on popularity and less about producing quality, soul-moving music that lasts.

Other American Idol-like shows such as The Voice, where the biggest pull has been the celebrity judges rather than the contestants, have not thrown up any winning megastars.

Singapore Idol, the local franchise of American Idol, ran in 2004, 2006 and 2009, with results pretty much similar to the United States show - first winner Taufik Batisah's music career is the only one to shine bright, eclipsing the other two winners who came after him, Hady Mirza and Sezairi Sezali.

While there are exceptions (the Taiwanese equivalent of American Idol, One Million Star, launched the careers of quite a few Mandopop stars, including Yoga Lin and Jam Hsiao), it would seem that winning a popularity contest is not the same as being able to get people to buy your music.

Perhaps the popularity of American Idol at the start was a case of the faceless masses beginning to fall in love with the power of their vote, and once the people had other outlets to exercise their power, they didn't need a TV show so much anymore.

It is no coincidence that the decline of American Idol's influence was parallel to the rise of social media's influence on pop culture.

Ratings for the show have been steadily declining in the last six years. At its peak in 2003, the second season where Ruben Studdard beat runner-up Clay Aiken, the finale show drew 38.1 million American viewers. The final season drew less than a third of those viewers.

Both American Idol and social media thrive on people power - the former relied on audience votes, while what goes viral on social media depends on users' clicks and shares.

Justin Bieber, one of the biggest pop stars in the world, found fame online through YouTube, releasing his debut EP in 2009.

Moving away from album sales, some of the more critically acclaimed and musically adventurous pop acts of today have also been discovered online.

Before he made his name as The Weeknd, Canadian singer-songwriter Abel Tesfaye uploaded his songs on YouTube, attracting the attention of influential online music media such as Pitchfork.

Today, he is one of the fastest rising names in modern pop. The music from his sophomore album, Beauty Behind The Madness (2015), picked up two gongs at the recent Grammys while his soundtrack contribution to Hollywood flick Fifty Shades Of Grey (2015), Earned It, was nominated for Best Original Song at this year's Oscars.

Nevertheless, there may be a limit to how far social media power can carry a music artist.

To date, Bieber, with 45 million records sold in the United States alone, is the only one who has found true superstardom through the Internet.

Many other Web-spawned singing stars, such as pop singer Carly Rae Jepsen, have not seen their initial viral popularity parlay into lasting fame. Incidentally, she was a finalist in Canadian Idol in 2007, but her global career took off only when Call Me Maybe went viral online and became one of the biggest pop hits in 2012.

Apart from Bieber, the true juggernauts of the current pop music world, the ones who came up in the last decade, achieved fame and sales success mostly through traditional music-business means.

Adele, the British queen of pop music sales, mostly has her record company, British indie label XL Recordings, to thank for developing her career.

While she did put up her early demos on MySpace, the biggest thing that the formerly popular social-media outlet did for her was to get her noticed by label executives.

Across the Atlantic, Taylor Swift went the Nashville route, making her name through the massively popular American country music industry before crossing over to mainstream pop.

Like Adele, Swift's rise owed much to the workings of another entreprising indie label, Big Machine Records.

Then there is British-Irish outfit One Direction, the world's biggest boy band, presently on indefinite hiatus. They, like Clarkson and Underwood, are also beholden to Cowell, not through American Idol, but through his other reality TV show, the British version of The X Factor.

But for them, as well as for Swift, social media was not the sole reason for their success - it served to strengthen their hold on pop culture after they became famous.

While American Idol-like shows seem to be on their way out, there is still a long way to go before real fan power by way of social media will be responsible for launching the bulk of the quality and lasting pop-music acts that can make a dent on the charts.

Remember, Beatlemania happened only after one man, George Martin, saw the raw gem that was the Fab Four.