5% off the total. Mainly it helps cover shipping.
I am buying Springs, shocks, and upper strutt mounts for Dad's Taurus. The shipping is 31.00, and the discount gets me 20.00 off. So essentially, I only pay 10 bucks for shipping.
I save a bunch of money over buying from the local parts store and I save on sales tax. The 5% discount helps cover the shipping.
Tom