sir.prize
A production assistant saw their video on YouTube and approached them to audition in front of the panel.
This is perfectly acceptable, because normally, acts would have to be seen by production assistants before going in front of the judges - and this had already been done...the production team knew what they were like already.
At the end of the day, if Simon, Alesha, David and Amanda didn't like them - they wouldn't have got through.
Lastly - their song 'Lovesick' will be number one within about three months, not because of Simon Cowell's well-oiled machine...but because it's ridiculously catchy.