Does post-loading data help web page loading performance?

Does loading unimportant data right after page load using AJAX help load the web page faster?

Certain modules on my web page are not essential so what I'm 开发者_如何学运维using is basically waiting for the basic web page to load and then loading the rest using:

<script>

$(document).ready(function() {

/* jQuery $.post statement to load data into specific divs */

});

</script>

Would this help loading performance or actually hinder it? If I remember correctly, Facebook does something like this, but I'm not exactly sure how (but I'm sure their system is much more elaborate and impressive)

it would only really help if;

a) your page was very, very large with a lot of images etc.

b) your code behind was either inefficient or slow due to other dependancies

b) if the post loading ultimately contributed to the overall UX.

On that last point, user experiance may be load time or when they select something that the data is loaded when requested in a smooth, quick and seamless manner.

that's my 2 cents worth anyway

I just answered a very similar question in the following SO question

Hopefully it will help you clarify some of your questions.