Thanx very much for the link Marcus, interesting reading. It looks like there are certain things to tweak to try influence it.
Do anyone have experience in this regard that they can add to this topic? Here is my situation, I have a group of 7 companies, represented on one website, now only one of them show on the sitelinks, the rest point to blog articles... so you can imagine it would be better to show companies on these sitelinks.