Well, the route was heavily promoted a few years back, when VA was starting it's new LAX-SYD/MEL/BNE service and loads of Brits boarded in London on their holidays with VS thru LAX on special fares - at least they were frequently on my flights.

I myself also used the westbound LHR-LAX-SYD route when Delta had double/triple miles promos to compete with VA and others.
Fares were about half of what they're currently