Originally Posted by apudme
So fast track is a ploy by BAA who runs the terminals to get high value clientele in the shops and spending for longer.
Hang on, I think matters are getting a little confused here.
There are two types of Fast track in operation in LON.
1. The Fast Track immigration line at arrivals, which the OP was asking about. AFAIK the US doesn't have anything like this (aside from the late INSPass).
2. Fast Track security lines at departures, which
apudme is referring to. Many US airports have these, and in fact go further than the UK by making them available to high status FFs as well as premium cabin pax.