Looks like Google is testing a new related content block that displays links to related content (so far news, searches, web pages). I’m assuming Google plans to allow publishers to modify the block to show links to other types of content like images, local, froogle, etc.

Garett Rogers says:

Since this doesn’t appear to show any advertisements, it is likely publishers won’t gain anything by using it — other than the satisfaction of knowing users are finding more information they are looking for. To solidify that point, the source code for the block doesn’t contain any unique identifier — required to link a website to a user account.

True, the source code doesn’t contain any unique identifier – but that doesn’t mean the public version won’t. Right now the outbound links from the content block do carry a client id. So Google is tracking where the visitors are coming from.

Web Page Link:

http://www.googlesyndication.com/relcontent/pageclick?

client=ca-rlu-vivi-ro-468x60_rc
&source=rlu&url=http://www.vivi.ro/blog/?p=182
&type=0&redir_url=http://romanian.joelonsoftware.com/

News Link:

http://www.googlesyndication.com/relcontent/pageclick?

client=ca-rlu-vivi-ro-468x60_rc
&source=rlu
&url=http://www.vivi.ro/blog/?p=182
&type=1
&redir_url=http://www.zf.ro/articole/Brokerii-nu-vad-motive-de-optimism-80250.html

Search Link:

http://www.googlesyndication.com/relcontent/searchclick?

client=ca-rlu-vivi-ro-468x60_rc
&type=2
&redir_url=http://www.google.com/search%3Frcu%3D2RLU%26hl%3Dro%26q%3DBANCURI

Example Script Include:
<script type=”text/javascript” language=”JavaScript”>
<!–
google_rc = new Object();
google_rc['width'] = 468;
google_rc['height'] = 60;
google_rc['modules'] = ['news','searches','pages'];
google_rc['color_line'] = ’336699′;
google_rc['color_link'] = ’0000ee’;
google_rc['color_bg'] = ‘ffffff’;
google_rc['color_text'] = ’000000′;
google_rc['color_source'] = ’6f6f6f’;
google_rc['color_header'] = ‘c6ddf4′;
google_rc['color_footer'] = ‘eeeeee’;
//–>
</script>
<script type=”text/javascript” language=”JavaScript” src=”http://www.googlesyndication.com/relcontent/show_rc.js”></script>

You’ll notice that you can choose which modules to display for the related content block.