Why Does Google trust some Joomla Sites more than others?

Search for Joomla (click here to try it) and you get something that has been apperaring more and more in Google search results.

Joomla.org is at the top with four extra links underneath:


Obviously, this is a pretty good situation to be in for any site, not only in the number one position for a search term, but with top 5 results.

So how do you get this benefit, which Google calls "Sitelinks". Well, there are certain requirements that your site needs to meet, which Google explains here. Basically, they say your site needs to be useful for visitors and easy for the googlebot to crawl. They also say that the whole process is completely automated, which led me to wonder what criteria sites need to meet. So, with help from Brian Teeman over at Joomla.org, I did some research using prominent Joomla sites:

 Age (Archive.org)
 Yahoo Links
Cached Pages   Page Rank
 Alexa Rank
Websites that DO have Sitelinks status      
Joomla.org 9-2005 3,380,000  184,000 398
Joomlashack.com 10-2005 263,000  23,000 7 4,303
Rockettheme.com 1-2006 888,000 26,400 4,794
IJoomla.com 1-2006 33,200 6,040
JoomlaSEO.net 11-2005  355 156 5 94,457
Phil-Taylor.com 5-2001 24,100
7 23,147
     Websites that DON’T have Sitelinks status
Alledia.com   – 5,940 735 5 47,011
CompassDesigns.net 11-2005 229,000  2,440 7
ELearningForce.biz   – 286
5 181,063
PixelsParadise.com  – 23,900  494  5
Sakic.net 05-2002  10,600
7 57,304
J-Prosolution.com  – 7,650 72 17,546

Clearly this is just a fraction of the statistics considered by Google but I wondered what can we learn from this brief overview:

  • Age is the single most important factor, although far from the only one.
  • Those sites with Sitelinks do have generally have more incoming links, more cached pages and a higher page rank. JoomlaSEO.net is clearly the odd one out here. Do they mainly by focusing on a very small niche?
  • A forum builds website size and helps a site reach "trusted status". The only site not in the top section with a strong forum is J-Prosolution. They have two problems – one is a relatively new site and the other is having their forum in a subdomain, which is thought to have a diluted effect on a sites rankings compared to a forum in the root. (See this link for a discussion)
  • Having a Site Map or even a Google Site Map doesn’t seem to be a big deal. I could only iJoomla.com and JoomlaSEO.net had either in the top six sites.

Any more thoughts on what distinguishes the top six from the other six are very welcome.