Google Sitelinks are primarily the links that are usually placed under a search result. These links can number anywhere between 4 and 8 as sub-links.
Over at the Webmaster World, there is a thread that is discussing the importance of sitelinks. Here are a few posts from that thread:
"Recently we had a Google site link change for our home page and we noticed a big dip in the serps. Google did not properly title the site link as it did in the past, so I went into webmaster tools and blocked the site link. When it asked me for a reason, I simply put that the page had the wrong title and put the correct title in.
Example: The Page is about "Widgets that are Green"
Google gave the site link as "Are Green"
Now, when I made this change, Google said the site link would be blocked until October 2nd. Anyone experiment with this feature yet and how did Google react in the Serps?"
"I've not seen any direct connection between ranking and sitelinks (blocked or otherwise) although sitelinks do give a good overview of how Google understands site structure. I would suggest that sitelinks are an effect, rather than a cause: site problems (especially structural or hierarchical ones) can be made more visible via sitelinks, but I don't think sitelinks themselves have any potential to cause ranking problems.
I would expect the impact of removing a sitelink on ranking to be nothing, aside from whatever changes occur to clickthrough rate as a result of the missing link or whatever replaced it."
It does look like they've done some updating recently – they just this past weekend added a sitelink to the most important event on my events site. Too bad the event was over two weeks ago. Be interesting to see if the link disappears now, since people won't be searching for it again until next year."
Well, here are the main points that came out of the entire discussion:
- Sitelinks do not directly influence your search rankings.
- Sitelinks can be removed but not changed via Webmaster Tools.
- Sitelinks appear to be constructed based on your site architecture, as Google understands it.
- Sitelinks can strongly influence your click-through rate on your search result listing.
- Sitelinks, when removed, can be gone as long as a year or more.
"Recently we had a Google site link change for our home page and we noticed a big dip in the serps. Google did not properly title the site link as it did in the past, so I went into webmaster tools and blocked the site link. When it asked me for a reason, I simply put that the
page had the wrong title and put the correct title in.
Example: The Page is about "Fiber Optic Lights"and has the proper title tag on the page
Google gave the site link as "Optic Lights"
Now, when I made this change, Google said the site link would be blocked until October 7th."
This, Googler Jonathan Simon replied, "Any Sitelinks you blocked should be removed from the search results soon if they haven't been already. Although we don't take action on Sitelinks feedback for a specific site, your feedback is appreciated and used along with the feedback of other Webmaster Tools users to find and fix issues with the overall system that auto generates Sitelinks. You can review your Sitelinks periodically in Webmaster Tools to see if new Sitelinks have been generated. "