What's with the sudden explosion of scripts running on web sites?

Red Squirrel said:

Even stuff like adsense, why is it javascript, when they could make it a php include or something instead? Would also make it harder for people to block.

Click to expand...

that wouldn't work... AdSense works by crawling the pages it serves. Server-side code would be prone to manipulation and you'd essentially have to give Google a backdoor into your site for it to work. Wouldn't fly.

Also a lot of jQuery to make things fancy-looking.