Are site links related to site quality? Does it tells the website or the page has higher quality? Do site links appear only for navigational queries?
JOHN MEULLER (Webmaster Analyst from Google):
I think to some extent there’s probably a quality aspect there in that we don’t show site links for any random website. But to a big extent, it’s really a matter of making it easier for users to find the specific content on a site. So if you’re entering the name of a really big website and you see it in the search results but actually what you wanted was this specific part of that website, then that’s something that we might say might make sense to actually show site links there. So it really kind of depends on the type of website, what we think is relevant for users, and how we can extract the structure of the website and make it easier for users to reach the right pages. So it’s not something I would say is kind of like a badge of honor that your website is really, really high quality. But rather people are looking for this specific piece of content on your website. So we want to make sure that they can actually find that piece of content as quickly as possible.