Buy 1 Get 1 Free Shopify Snippet!
This article will teach you how to install a snippet into your Shopify store that will allow you to run a "buy X get Y" deal. I had a client who wanted to give a free yoga mat to any customer who purchased 5 items from their yoga apparel collection. I have taken this code and generalized it for your use!
I at first looked to see if some combination of apps could accomplish what I was trying to do. I found that I could hack the behavior they wanted together from a franken-install of no less than FOUR apps. That isn't exactly an elegant execution. On top of that, it still allowed their customers to cheat the system!
Zach Lukaszek, co-Founder of Ships-A-Lot