Sitelinks in Google: PPC and SEO
Google made Ad Sitelinks available to all AdWords campaigns. Previously only top performing ads could show two-line or one-line sitelinks and experience, according to Google, a 30% CTR increase.
To add Sitelinks to your campaign (Ad Sitelinks will be the same for all ads in your campaign) you need to select the “Show additional links on my site” option in the “Ad Extensions” section under the Campaign Settings tab.
You can select up to ten links, but only 4 will be eventually chosen, depending on the keyword that triggered the ad and the ad’s quality score.

As you can see in the screenshot example above, Ad Sitelinks offer opportunities to segment users and direct them further down the purchase funnel. It’s also possible to organise Ad Sitelinks according to brand segmentation or direct users to the most converting pages, choosing brief but effective ad text for the links.
SEO for sitelinks in organic search results
Sitelinks are one of the solutions Google implemented to offer enhanced listings in natural search results, providing more options to users by allowing them to jump directly to important pages of a site, bypassing the homepage and navigation menu.
Pages ranked at the top position on the SERP can show eight sitelinks, arranged in two columns; other search results will feature up to four sitelinks listed in one single row above the URL.

Users can have an overview of a site’s structure and best content before choosing a search result over another, but not all sites will have sitelinks and they would be automatically generated by Google’s algorithms. In this example it’s interesting to see two different anchors Google used for the same destination page, “Streaming” and “Calcio Streaming”.
In fact webmasters cannot choose which pages would appear as sitelinks or the link text, but it’s possible to exclude a page from sitelinks from Google Webmaster Tools.
How to get sitelinks for your website on Google
Google hasn’t revealed the algorithm behind sitelinks: Webmasters can only speculate about it and test different theories.
Sites that show sitelinks in search results are well structured, have a clear hierarchy and consistent text links. Search engines need to be able to navigate the site, understand the navigation hierarchy, the meaning of categories and the topic of sub-pages.
According to Bill Slawski of SEO by the SEA, an authority in analyzing search engine patents, sitelinks would appear to help users in navigational queries. Pages could be shown depending on log file analysis and data collected from Google Toolbar: Web page popularity would be a primary factor, determined by CTR, traffic data and links pointing to the page.
Ann Smarty lists six educated theories that could explain the factors concurring in generating sitelinks. Traffic data, on-page SEO and internal architecture are confirmed as important factors, but domain authority, brand strength and the absence of competition on specific queries would also influence the appearance of sitelinks.
