2. Simple integration with your website: Understand how much work it will take to integrate a payment processor into your site. Hint: it can take a long time, but it doesn't have to. Depending upon your IT sophistication, some payment processors offer a hosted checkout option that can let you go from a merchant account application to accepting online payments in an hour. Other payment processors offer application programming interfaces (APIs), which allow you to mesh the processor's code into your own site for complete control over the buyer's checkout experience. And many payment processors are pre-integrated with a wide range of shopping cart software and e-commerce platforms, so you won't have to change as much of your existing website infrastructure.