This is timely considering we’re working through the checkout and payment process of our own e-commerce plugin for WordPress.

Some interesting highlights:

• We have to support 4 types of shoppers:
  1. known-item purchases;
  2. category research, where users identify and buy products that best match their needs;
  3. bargain-hunting; and
  4. browsing for inspiration.
• We need to devote more time to search than I was initially considering

E-Commerce Usability Jakob Nielsen’s Alertbox.