You do not have to have google analytics you need a google sitemap and submit it to your webmaster tool .
You do not have to have google analytics you need a google sitemap and submit it to your webmaster tool .
Based on that, I think that what matters is how many of your pages are indexed for a particular keyword. If someone searches for something and your site comes up with more than one page that is indexed for that term then google will show the main indexed page, and then put the other sitelinks under it. If there is more than just a few, then it will include a "more similar pages" link under those sub listings.
So I think if you just work on getting more pages of your site indexed for the same keywords, then that's what will get the sublistings in the serp as well.
@Arraial - OK I was doing a search and noticed what I think your actually talking about. My previouse responses were talking about having multiple subpages listed under your main listing in the serp.
If you're talking about the sites that have a box under their listing that has the sitelinks in it then thats a different thing. I've noticed a lot of BIG sites, especially ecommerce type sites will have a box under their listing that has a table of sitelinks for the various categories in their store.
I don't know what the criteria is for getting that sitelink box. Google says that they create the sitelinks based on whether it seems suitable based on the structure of your site. That makes me think that if you can make sure that the site is divided into well defined categories, and then you have a good sitemap that really lays everything out based on that structure then you'll have a better chance getting that.
The only thing I've ever had for my own sites is the sublistings in the serp. Getting that sitelink box would be pretty cool.