I've had quite a few calls and emails about this over the last month or so - thus this post with some general advice:
- You will find that most retail POS systems only work with certain e-commerce site and vice versa. It is not a universal solution in most cases. Be prepared for this and realize that your choice of POS software may dictate the e-commerce options available to you (or vice versa).
- There are some exceptions but the complexity of a POS system usually drives the e-commerce options.
- Custom development of an e-commerce site may be an option for retailers who have a large online presence.