Joe-music.com was built by digital agency MadeByPi and went live immediately after McElderry was revealed as the winner of the competition, earning himself a £1m contract with Syco, Simon Cowell's division of Sony BMG.
In case either of McElderry's two rivals, Stacey Solomon and Olly Murs, won the competition on its final weekend, versions of the website in their names were prepared as well.
Dan Ayers, Sony Music's director of digital services said: "Building the winner's site is always a time-pressured process. Effectively we have the week before the final to build three sites, all with robust community functionality considered as standard."
The site carries links to various retailers selling the digital and physical versions of McElderry's cover of Miley Cyrus' 'The Climb'.
No pricing details are given, meaning consumers could pay as much as 99p to iTunes and 7digital, or as little as 29p to Tesco.
Tesco has grabbed headlines by selling the single at half the normal price in a bid to up the appeal of its download store, but has seen its offer matched by Amazon.
HMV is selling the single for 79p and ismarketing it via its almost one million strong customer database as well as using paid search marketing around terms such as 'X factor single 2009'.
A look at Google Trends today reveals Joe McElderry at number three in the top 10 hot topics and 'X Factor' winners at number six.
But rap-metal band Rage Against The Machine is at number nine, indicating the strength of the internet campaign intended to derail the Cowell empire's tilt for the Christmas number one by telling people to buy Rage Against The Machine's single 'Killing In The Name Of'.
Bookies are unconvinced though, slashing the odds for McElderry to secure the number one spot to 1-8.
The extent to which 'X Factor' has grabbed people's attention online is also illustrated by viewing figures released for ITV.com.
The number of unique users on the 'X Factor' section of the site was up 77% from last year to 821,000.
Video views were up 61% to 30.5 million and on the final weekend the site gained 1.9 million video views.