One of the biggest problem with ajax is that google has a lot of problem crawling your website.
The biggest problems is with paginated lists. There are many ways to solve the problem.
in the .NEt world everything is already there, waiting for you to find and use it
<asp:DataPager has a very useful parameter called QueryStringField.
If you specify that field, the control is rendered as a list of hyperlink instead of a postback control.
With some server side code you can set that parameter only if the user agent is a crawler, or you can add more complex logics behind it.
This simple change on your website will allow google to crawl a lot more pages on your website and increase the organic traffic on your site