Give a product for free with any purchase

I would like to make a limited time offer where buyers who buy any item in a certain category get another product for free. So anyone who buys a product in category x gets a free copy of product y.

What is the easiest way to do this?

Hi Jeremy,

This is not possible in Hikashop at the moment. However you have few solutions to do that kind of thing.
1 - First you can simply add a message during the checkout process to inform your client that they are going to get a free product with their order. In this case, you just have to edit the cart view (Display>View) and add this message in the file.
2 - Second, you can give your client a coupon of 100% reduction which allow them to buy the given product for free. But they'll have to make a second order.
3 - You can also create an autoloaded coupon of value 0 which will be named for example "the free product" and will appear in the cart during the checkout.

If you to add the given product to the cart each time someone add something to the cart, it almost impossible. You'll have to edit many files in hard code and that's wouldn't be easy to implement/remove.
Bt if it's what you want I can try to help you

Hi Eliot,

I don't think we'll do the hardcode way - I don't have the time at the moment for that. Hopefully you guys will consider this for a future feature! This is not just useful for promotions, but product bundles. That way you can have a single bundle product deliver the contents of a bunch of other products. Very quick and easy that way.

And the other ways you suggest won't look very good (though I appreciate you giving me the option). I will instead update each order manually with the free product. Labour intensive, yes