I haven't done anything in sales since I was in college.. I don't actually remember hearing this term myself. I learned it later from my brother. He sold cars for a while and then mobile phones for a while. Spiff is very frequently used in auto sales, they've got a gigantic complex constantly changing set of spiffs from both the dealer & manufactuer(s). I guess it's probably been 10 years since he quit selling cars though so maybe it's gone there too! I had a couple sales jobs selling computers in college. The "spiff" at CompUSA was for trying to scam people into buying a 3-way package of: a) Overpriced printer cable b) 50 sheets of aper c) Useless printer warranty. If you sold that package to someone they gave you $50! Didn't stay at CompUSA very long.. almost fell off a ladder trying to get a giant CRT down in the warehouse and skipped out of there.