Auto add free product when ordering certain products?

i've been to stores before where it automatically adds a kit to your cart ... is there a way to do that in Zen Cart? For example a customer orders $5 at the store and they get a collab kit free. It would be awesome if it just added it automatically to their cart once they have $5.00 worth of product in their cart. Or will I need to do it as a coupon where they have to add the $5 worth and the collab and then use a coupon code.

Not to my knowledge, and I wish there was. I promise a free gift with every purckase, and I set up a "free with purchase" category to let them choose whether they want fragrance oil, a scented tealight, or a piece of fabric. Some customers see that and choose, some don't and then I add whatever I choose.

It can be done, but you would have to code it yourself. There is a thorough discussion of this process as an example in the wiki, somewhere in the Developers area I think.

http://www.zen-cart.com/wiki/index.php/Developers_API_Tutorials#Another_Real_World_Example