Ninety percent of frequent shoppers -- those people that buy something online at least once a week -- use shopping carts to save items that they plan to purchase later, according to a study from Bronto and Magento. The report also revealed that 83 percent of occasional shoppers -- those people who buy online at least once a month -- also use the shopping cart to save items to buy later. Forty-seven percent of those shoppers expect to receive a reminder email after they abandon these carts, the research concluded.