Recommendations for Smart Upsell: Fully automated Upsell & cross-sell based on API software recommendations. Focus on your market and let the AI app handle upselling. Building successful product upselling, cross-selling programs, and promotions to increase sales. Create your own upsales or use one of our predefined ones. The Slick One Click Upsell app offers slick upsells, cross-sales, gifts & related package packages through pop-ups. The Upsell is in the cart and One Click is in the cart.