1 or 20 doesnt matter - for any N>0 only one company can do "top N", not all of them who pretend to achieve that, and they wouldn't be able to pretend it if the

1 or 20 doesnt matter - for any N>0 only one company can do "top N", not all of them who pretend to achieve that, and they wouldn't be able to pretend it if they used the random approach like the GGP suggested.