Whether it's a loose wheel that always seems to be faced in the wrong direction or a wheel so sticky that it'll barely turn, a wonky shopping cart can ruin a trip at the store. And the same goes for online shopping. If a website's shopping cart doesn't function properly and doesn't follow best practices, an online experience can easily be spoiled. Because eCommerce spending is capturing more retail market share every year, and because there are so many new players coming on...