THE RULES HAVE A LOT OF PARAMETERS THAT YOU DEFINE WHETHER OR NOT TO TRIGGER THE RULE:

• products already in the cart
• cart amount (min and max)
• number of distinct products in the cart
• total weight of all items in the cart
• coupon redeemed
• parent rule validated

THESE RULES CAN BE FILTERED TO APPLY ONLY ON SOME SPECIFIC

• categories
• shoppers group
• manufacturers

THEN WHEN THE RULE IS TRIGGERED, YOU CAN EITHER

• give a percentage or amount rebate using Virtuemart coupons or AWO Coupons
• Define a custom price for an existing product (via custom field plugin)
• add one or several products
• select one product from a list
• force product removal
• display a congrats! message

WHEN A RULE IS NOT YET VALID

• Display an incentive message
• Block checkout (useful if you need to have your customers to buy a combo of products for example)

AND SEVERAL MORE SETTINGS:

• Adds a category 'Bonus' unpublished where you can store your bonus products but not display them in your catalog.
• Optional check stocks. (ie. You can offer the bonus product while some are available or at any time)
• Optional check minimum order quantities. (ie, if you have it set to 2, you'll need a set of 2 master products to have the bonus product added)
• Optional check maximum order quantities. (ie, if you have it set to 3 and have a set of 5 master products in cart, only 3 bonus products will be added)
• Not possible to add the bonus product directly in cart, it will be removed if the master products are not there.
• There is absolutly no hack to core Joomla or Virtuemart component.
• Upsell in customer's cart !
• Compatible with Virtuemart 3