The chief criteria for judging an ecommerce shopping cart are the number of credit card processors and shipping services it supports, and the number of people that support *it*.Why? Because credit card processors and shipping services mutate all the time. Your cart will require updating. Which service works today may go out of business tomorrow, and leave you with the orders piling up.Other important criteria are how easy it is to set up, and add products, and how easy it is for the customer to .