Employers and retailers arent even a comparison. There are many other retailers to choose from as most of us will. Performance is NOT the lowest priced retailer and does NOT have the best service. Their prices are actually higher than most and shipping times are 3+ weeks. So unless to give us buyers a reason to use them (20% off) most us will go elsewhere. Its called capitalism, look into it!

your employer makes money off you even before you give him 20% off. There is no reason to discount work.