it all depends on how you use it. i've seen a clutch in a corolla last 170k, i've had a clutch in an eclipse gst last 150k with racing and bulls***, i've seen others with the same car last only 70k. its kinda the same as asking how long the stock mazda brake pads will last to put it in a different perspective.
I have 21000 miles on the clock and have had the turbo kit in the car for about 3k of those miles, and the clutch is still as sticky as the day I bought it. I have been to the track 3 times (probably totalling about 25 runs), but drive it pretty easy around town.