This goes hand-in-hand with cart abandonment emails. Recommendation blocks (upsell and cross-sell) are great at making your customers buy a little extra, but they can also be used to tempt clients into choosing to go through with their current purchase.
How would that work? You show a site visitor products related to the one he or she currently has in cart, which might just incidentally be products you have on discount - and thus up the customer's intent to buy on your site - especially if related products can be quickly added to cart without interrupting the checkout flow.
If you are wondering how to integrate recommendation blocks across your store, we have a simple and elegant solution: Searchanise. Our upsell and cross-sell widgets come right out of the box and are easy to install, while offering great flexibility. It's just one of the many tools we offer to increase your store's conversion, by the way, alongside a smart search box and customizable filters