The apple category in Germany has 90% market penetration. The difference between the total population and the apple buyers therefore is negligible – apple buyers practically are the population. Also there are hardly any profile differences among the apple brands / species.
The reach of this phenomenom extends from sociodemographics to brand values. In Automotive for example every driver thinks of his car that it is safe – with practically the same weight for all drivers of almost all car brands. Also media behaviour hardly differs among brand buyers, which is an extra argument to create distinctive advertising – unique and standing out from all other brands in the category.