There´s a big difference in how things are done in Europe and in the US. As Mr. Voigt points out maintaining own visual separation works fine and is very efficient, especially, in my opinion, when very different types of aircraft are involved, such as a small commuter following a heavy. The little guy, without ATC mandated separation, can stay higher and faster much longer, and touch down at a point well beyond the heavy and thereby avoid any wake. Go to any major U.S. airport with a variety of traffic and watch the guys plant their wheels the moment the aircraft ahead clears the runway.
In Europe this is almost unheard of, and most pilots are loath to accept the added responsibilty (a culture thing?).
The only airport in Europe where this wouldn´t add any benefits is LHR, as the controllers there are allready keeping spacing to a minimum (well done).