Retargeting abandoned carts may boost conversion rates up to 26%. Some customers may not be ready to convert. In those cases, it is best to retarget them with ads or emails (if you have their email addresses,) so that they will return to your site to complete their conversion when they are ready. Take note that there are different groups you will need to retarget separately: cart abandoners, first-time visitors, repeat customers, recent visitors. Consider using a tool like Perfect Audience.