Many webmasters are using Ajax to improve the user experience on their web sites, but Ajax can make the site difficult for search engines to crawl and index if the technology is not implemented carefully.
Five Practical Uses of AJAX:
1. Login Forms
Instead of going to a login page, and then navigating back to the page from where you are, with AJAX, a user can login directly into the original page. From there AJAX will send a request to the server to log them in. The server let’s the page know they’ve been logged in, and the page you are on can update as needed.
Google’s search suggestion tool, one of the auto-complete tools made based on AJAX, when you typing in the Google search bar, it show you common results using AJAX.
3. Voting and Rating
Most of the Social Bookmarking sites have option like Rating and Voting, to know which content is helpful for users. They use AJAX to handle all of the voting, so that the users are able to voice their opinions on a number of stories quickly and easily.
4. Updating With User Content
Twitter is more popular with its simple user interface. When someone added a tweet, it is instantly added to their feed. Twitter is updating their page content using AJAX. Twitter search results that come out when there are new tweets with search word, real time link tracking that updates its charts for every 5 seconds.
5. Form Submission & Validation
AJAX can create a highly responsive web interface and increase the user experience. AJAX make Forms a lot better for the users. Most of the websites use AJAX to check the forms to meet their requirements such as password strength, valid mail id or URL and some missing columns in form.
For Example: JQuery Form Plugins
Though the change doesn’t mean that Googlebot can read or index personal comments on Facebook wall, it means that if you use the social networks to login to certain websites, those comments can be indexed and can come up in search results. Besides Facebook, remaining services such as Intense Debate, Disqus can also be indexed
SEO benefits of using these changes:
According to the HTTP specifications, URLs refer to the same document regardless of the fragment identifier (the part after the hash mark).
With these new changes, when we use the #! Notations the crawler knows that the link refers to additional content. So the pages of the site which came after # are also indexed. The crawler transforms this URL into another URL and requests it from your web server. The web server is supposed to respond with static HTML representing the AJAX content.