Since Internet Marketing and web design are so closely intertwined, it makes sense to take a close look at the AJAX web application design trend and how it impacts your web site.  

AJAX is simply a way of creating more dynamic web sites that respond to user requests on the browser rather than going back to the server to refresh a page.

Alex Bosworth has a great list of AJAX Mistakes that warrant some consideration. The "Blocking Spidering" is the most pertinent mistake item when it comes to optimizing your web page for search engines.

With search engines, you very rarely get a second chance at first impressions. By this I mean that once a robot or spider has visited a page and stored its content, it typically expects links on that page to refer to other pages; not dynamically alter the current page as AJAX does.

i-Dialogue incorporates some AJAX techniques for the admin/design interface, but for the customer facing experience we prefer to leave as much the site as static as possible. Namely because robots and spiders want to know what your page offers when they visit, and if they must traverse through an infinite number of dynamic links they will most often give up and assume their first impression of your page is the best impression.

Exceptions to this rule might occur when providing a lead capture or profiling form to a user that can be asynchronously sent back to the server for processing while the user just sees an "Updating our records..." message. This lets the user continue contemplating what action to do next in the portal without disrupting the experience.