Today I learnt why Google shows a second search result when you search for a websites name, even though the first result has sitelinks. You can see how TechCrunch has a second listing about the Google phone in the image below:
When this first started happening people assumed it was a bug but Matt confirms it is intentional:
you asked why we still show a second result from e.g. starbucks.com even if we show Sitelinks for starbucks.com at the #1 slot. That is intentional (not a bug), and the reason is that some people don’t notice the Sitelinks. We’ve done lots of UI tests to make the Sitelinks have the right amount of visibility, but showing a second result helps in those cases when people don’t notice the Sitelinks, which does happen.
So there you go. I think the algorithm to determine the second listing is to do with pages that have had the most links in the past few months.