What is 'pop music'?

When analysing the term pop music the majority of us would recollect the cringe worthy one-hit wonders of recent years such as The Cheeky Girls, Mr Blobby and Bob the Builder. All of whom have released single and managed to get into the Top 10 charts. When I address pop music as a style I cant pinpoint it in any direct manner. Looking at pop acts in general as a mediated package, Justin Timberlakes, Britneys Spears and The Spice Girls are all used to sell their consumer a product of which has become popular music.
However when you address this on a larger scale and look at artists individually such as Pavarotti who in recent years has appeared in the popular music charts you begin to wonder if the term pop music is based on individual tastes and preferences of the majority, at any one time. Within each genre there are artists that reach commercial success and outsell their competitiors. Opera artists such as Katherine Jenkins and Russell Watsons are evidently proof that these sorts of artists can reach commercial success and prove popular within their genre. Particularly singer Charlotte Church has recently emerged onto the stereotypical ''pop music'' scene. Charlotte, a opera singer who received critical acclaim and merged into the field of ''pop music'' where there is focus on target market and selling music as an image based product.
The debate in that respect can fall into several topics. 1.Pop music being records that are successful in their genre (ie) Rn B, Rock and Opera that and sell as good music. 2. Those artists who are intentionally devised as a product marketed at an audience to make money.