Ajax Crawling: old way vs new way (#!)

The idea is to make the AJAX applications crawlable. According to the HTTP specifications, URLs refer to the same document regardless of the fragment identifier (the part after the hash mark). Therefore search engines ignore the fragment identifier: if you have a link to www.example.com/page#content, the crawler will simply request www.example.com/page.

With the new schemes, when you use the #! notation the crawler knows that the link refers to additional content. The crawler transforms the URL into another (ugly) URL and requests it from your web server. The web server is supposed to respond with static HTML representing the AJAX content.

EDIT Regarding the original question: if you already had regular links to static pages, then this scheme doesn't help you.

The advantage is not really applicable for you, because you are using progressive enhancement. The new Google feature is for applications written entirely in Javascript, which therefore can't be read by the crawler. I don't think you need to do anything here.

The idea behind it is that Javascript users can bookmark pages too, I think. If you take a look at your 'old' method, it's just replacing content on the page; there is no way to copy the URL to show the page in current state to other people.

So, if you've implemented the new #! method, you have to make sure that these URLs point to the correct pages, through Javascript.