The least common reason customers abandon a shopping cart is that they don’t like the product. More common are second thoughts on shipping costs, total cost, payment options or security concerns. If you simply ask them to come back via email, at least 15% typically will do so.
If someone leaves an item in their cart, it’s a good idea to remind them of what they've left behind. A simple reminder or a small incentive or closer offer (i.e. free shipping) is often all that's required to get the deal across the finish line.