Boy bands, Girls bands.

I am no aficionado when it comes to music/ dance of any genre. Yes, some music stirs me, some music saddens me, some music lulls me, some music makes me throw up (right, some video game, made me do that),....
Why are some boy bands and girl bands so successful? By now, everybody knows it's more about marketing than about talent. (whatever be the definition of talent) Planted stories, same sex preferences, wardrobe malfunctioning, ..But still we give in and keep buying, listening stuff. So that atleast few artists (and their troupes), labels, executives become millionaires.
Why? Is it because, we need to like somebody, even if that somebody is nobody? We remember Bach, Mozart..Will somebody in 2126 AD remember britney, madonna, usher, spice girls?