I've had the number one position for a pretty major keyword for several years now. However, I don't have those additional listings that google often puts under the first serp. To get those, would I need to file a sitemap with google? Or is there anything else I can do to encourage google to place those (what are they called?) under my listing? Thanks, Chris
http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=47334 There is no specific thing you can do to get site links generated with your search results, Google generates these on their own. Common theory and belief from what Google has stated is proper internal linking and a valid internal structure is the key to getting accurate site links.
I've noticed that it appears to be high-traffic sites that get site links in the SERPS. That said, some smaller sites have them as well - so who really knows!
Basically I have had the same problem for a few sites im involved with this is what I have found: Its a combination of things I think: People actually looking for your site ie searching for your site name. Deep links, other sites linking to sub pages rather than the home page, suggesting to google a need for deep links in the serp results. Fairly large site seems to help as well Old site, the older and more established the site is the more likely it is to get those sub links However its important to remember that they give you no real advantage other than for the keywords they appear for, however another advantage is it makes you alot more invunerable in that you can pile in a load of links without getting banned or a -30 as easily.
I would say union's reply sum it all up. Just one more point would like to add: Your site needs to be no.1 consistantly for that keyword. I would say atleast 3 months. My site has sitelinks for multiple keywords and its already a authority.
One of my sites with sitelinks is small (less than 50 pages), has less than 50 visitors per day, and almost no one links to it - it's been pretty much neglected for a year or more. On the plus side it is more than 2 years old and has been number 1 for its main keyword for a year or so. The keyword is not in the domain name and no-one searches for the domain name.