Very interesting. "camber garage doors" gives sitelinks, but "camber garage doors uk" doesn't.
It appears the sitelinks are only presented when there is a very close match between what the searcher is looking for and the actual site.
Sitelinks are only being presented when there is almost no ambiguity about which site the searcher wants.
IMO I think this means Google is taking advantage of the fact that many people type the intended sitename into the Google search bar, not the browser address bar.
Presenting sitelinks to these people makes Google even more convenient, so it encourages them to use Google again in future.
This works on all the sites I've tried so far. All these searches present sitelinks:
yahoo
dani web
camber garage doors
the age
the economist
asx (For
www.asx.com.au)
Its uncanny how reliably sitelinks will be presented, if you search in this way!
Also, I've noticed that if the domain is several compound words, Google will not present sitelinks; eg, "cambergaragedoors" no sitelinks, but "camber garage doors" gives sitelinks. However the short two word examples above like "daniweb" or "theage" get the sitelinks regardless of whether the words are run together or not. ("dani web" gets sitelinks and so does "daniweb")
I'm guessing there is too much processing (and possibility for errors) to parse longer strings into separate words, so Google are only doing it for shorter domain names. It still presents the same site at number 1, but the sitelinks index must still be separate from the main Google index, so they don't present sitelinks for that site (yet). I'm fairly sure they will be merging the indexes as its such a useful feature, but they probably are not ready to do it yet.
I'll bet for the moment there is a domain name length at which Sitelinks turn off. Hmmmm implications for buyers of domain names, shorter is better (but we knew that anyway...).
M