I know I have already once talked about sitelinks, and today I would again like to post some lines about the sitelinks.
So what are sitelinks? Google sitelinks are little set of links or snippets of links seen in SERPs just below the website URL.These list of links ranges from 2 to maximum number of 8 links.

Here's a screen shot of the popular photo collection website from Netherlands.

The links highlighted are called Sitelinks and they are the sitelinks for the Search with "photoos" in, you can see the above result.Here are few points I would like to mention for the sitelinks as I have experienced:-
  1. Site should rank first for the keyword used as query to search.
  2. Searching for short, high traffic keyword/s usually brand/domain names.
  3. Not for every keywords or keyphrase sitelinks appear.
  4. Fairly high natural search traffic.
  5. High click through rates from the search results page.
  6. Sitelinks are usually generated from top level links. Internal links from homepage.
  7. Easily crawled, structured navigation. Easy to crawl and relevant page links in HTML, Useful links.
  8. Pure HTML links, no java script or flash.
  9. Image with proper alt text.
  10. 2 to 8 numbers of sitelinks are displayed.
  11. Site age is several years or older.
  12. High probablity that the information on a web page will be accessed by a user.
  13. High probablity that the information will be useful to a user submitting a search query.

Google says, "Sitelinks are calculated algorithmically and completely automated".
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