simple discount for shop items and booking services.
of course for a limited time.
If you do it using coupons the user has to chose the correct voucher, but the customer - unable to cope - may leave without buying anything.
One easy solution could be to make vouchers *audomatic* so they are always active.
So when you create a voucher there would be a checkbox
[x] Voucher always active
another way to do this:
you can already enter discounts for shop items. But you cannot limit the discount to a time yet. Should be easy to implent.