The Little Black Book of Online Business: 1001 Insider Resources Every Business Owner Needs

Chapter 26. E-Commerce Integrated Systems

These services typically combine most of the common functions in a tightly integrated system, including shopping carts, autoresponders, affiliate program functions, subscription systems, and digital product delivery systems.

These systems will give you the most bang for your buck—in some cases the flexibility isn't as great as with separate component systems, but there's less hassle involved.

http://www.infopia.com/

http://www.infusionsoft.com/

http://www.1shoppingcart.com/

http://www.memberspeed.com/

http://www.fantasos.com/

http://www.quickpaypro.com/

http://www.goldbar.net/

http://www.volusion.com/

http://www.synergyx.com/ (disclosure: I own this site)

Consider using a dedicated autoresponder–e-mail service when possible, even if your integrated system includes these functions.

The reason I say this is because, in my experience, the companies who focus on e-mail solutions have a better e-mail delivery rate.