What about a Spin to Win?
 

We are now looking at a Spin to Win wheel with 5%, 10%, 15%, 20%, 25% 50% off categories.
Here's how it would work...
Come in to buy what you want in certain categories or name brands that week (Clifford; Focal; JL Audio; Thinkware; Compustar; Redenso...). You find what you like, but before you pay for it, you spin to get the discount. 1 spin per person per purchase.

What do you think?

I personally hate those kind of promotions. I want to know how much I’m paying before I get in my car. But I may not be typical.

Nope ... prefer to know the discount and sale price before I commit as well. Especially when we're talking mostly big ticket items into the hundreds. Save the spin and wheel for the carnival.

5% would be too low to entice me to want to spin.
What about a leveled discount
Spend $100 get 10%
Spend $200 get 20%
Spend $400 get 30%