An excellent article on MarketingSherpa showcases how a great performing shopping cart can perform even better. Adagio Tea had a below-average abandon rate (35% compared to the 59.8% industry average). They offered a $5 gift certificate to incent people who had abandoned their shopping cart. Test emails were sent at a minimum three days after a cart abandon and maximum six days after. The results?

The campaign has performed admirably for 18 months now, and Kreymerman recommends other ecommerce sites test something similar.

They’re seeing a 5.6% lift in conversions from the shoppers who receive the email. Source

The lift you receive will vary greatly on your audience, your offer, and for some markets, seasonality, but auto-emails should definitely be on your short list of techniques to test. This presumes you capture the users email on a landing page or early in the cart process. When capturing emails, you should also highlight a ‘No spam’ policy, usually a simple sentence to help encourage the resultant user.