What's up with the #! in twitter & Facebook URL's?

[KevinBarnes]

I was just wondering why Facebook and now Twitter have added "#!" into the url structure? Does this mean we should link to a twitter profile like this - twitter.com/profile -  anymore?

Should we now be linking like this: twitter.com/#!/kevinbarnes

Kevin

[Highland]

The short answer

The character ! is added only for Google purposes, this notation is a Google "standard" for crawling web sites intensive on AJAX (in the extreme Single Page Interface web sites). When Google's crawler finds an URL with #! it knows that an alternative conventional URL exists providing the same page "state" but in this case on load time.

http://stackoverflow.com/questions/3009380/whats-the-shebang-hashbang-in-facebook-and-new-twitter-urls-for

[KeriMorgret]

Highland is right, this is for indexing of ajax. I personally leave out the #! when linking, but that decision is based on I'm usually sending the link in email and those characters sometimes break the hyperlink.

[seanmccauley]

aka hash bang