Is it just to try to have the largest share of the toothpaste shelving in the supermarket? There seem to be about 8 different types on sale when you look through: ones that whiten; fizzing ones; striped ones; gum strengthening; enamel strengthening; breath freshening; long-acting of one or some of the previous list...
Why not do one that does everything and one that's just 'standard'. Maybe 'Total' does everything but it's not entirely clear from browing the packages. In the end I just pick whatever one's on special offer. It seems a waste, though.
Yeah, yeah: tl;dr. :D