Jeffrey Zeldman hat sich die Top 100 der US-Websites angesehen (Basis Alexa Traffic). Er stellt u.a. auch die Frage danach, wie sich Websites nach der Schlüsselübergabe weiterentwickeln.

Interessant ist in diesem Zusammenhang folgende Vermutung.

This preference for Strict among non-validating sites suggests that at one point these sites were made over by standards-aware developers; but that any standards improvements made to these sites were lost by subsequent developers.

Web Standards Test: Top 100 Sites