The user’s processor does the code execution here. This saves bandwidth for the web server.
The language is user friendly. The faster execution and low bandwidth utilization of the web server is beneficial for the users.
Availability of Third Party Addons
The language enables developers and users to add functionality to websites using code snippets.
Easier Site Maintenance
1) Faster response time with performance and speed improvement
2) Faster traffic between client and server
3) Firefox add-on makes it easy to debug Ajax call.
4) Get access to JS Libraries like Query, Prototype, Scriptural, etc.
5) AJAX websites are easier to navigate than traditional ones
Here is an info-graphic that tells you more: Future of Web development
1. Zero billing guarantee