I want to add a shopping cart rule to my site which gives a discount every 3rd item. For example if there are 3 items for a category in the cart, provide a discount of £2, and when there are 6 items, apply discount of £4 etc. I also have to consider if a customer buys 4 or 5 they'd get the discount set on buying 3 etc. Is it possible to do this with a single rule?
Thanks in advance.