Some merchants increased sales in physical stores when putting up Special Offers in the form of Half-priced beanies for every Tank or Tee!, or Buy two, get one free, or Buy a pair of shoes, get 40% off from any bag etc.
For Shopify, we developed an app to allow you to make these kinds of offers, with various customizations and Upsell messaging appearing in cart.
We're in the final testing stages before publishing to App Store. If you'd like to give it a try now, we're glad to offer two free months of usage. Then you can decide if it's really suited for your shop or not. To request access, email firstname.lastname@example.org
Thanks and have a sunny day!