With all the sites out there competing for professional photographers, it's daunting to find one that's just right for your business. No single way of doing business is right for every photographer. For example, some photographers already have a method of taking credit card payments, so they may prefer to leave the money collecting to their own staff, while other photographers will be happier leaving all that complexity to the photo Web site.
This table is designed to give you an idea of what the site offers, not represent a complete compendium of each site's abilities and practices. If the Custom materials section mentions mouse pads, then that site does offer mouse pads; but that doesn't necessarily mean that another site doesn't offer them, or that one of their lab partners doesn't have them. They might. This table is a jumping off point, where you can examine the different kinds of sites and investigate further. There are too many photo proofing and printing websites out there to list all of them, with more popping up as this table was compiled. These are some of the most prominent, and you should feel confident giving any one of them a closer look.