I know what they claim are their sources, very vaguely put but there are some real anomalies here. At random, one question is about two singles I remember were mega in my early days and they don’t appear on the list:
Ike and Tina turner: River Deep Mountain High
Sonny and Cher: I Got You Babe.
They simply don’t appear. Why not? The Rolling Stones aren’t in there and yet Satisfaction sold megacopies in its day, all around the world. A Whiter Shade of Pale does appear, so that at least is all right.
Also, there are so many artists on there who are new, since music went to the pits – all these rappers and so on. But as total copies sold also presupposes history, i.e. people of an older bracket, as it presupposes that artists take years to build up numbers, now could Gaga be up there?
One answer is that they are including online “sales”, something which wasn’t available to the old artists. Rebecca Black’s dross Friday is a perfect example of millions hearing it on Youtube.
So, of what value are any lists of “best selling” any more?