New WebParts Recommended Items and Popular Items have been introduced in the SharePoint 2013. These are the part of new "Content Recommendations" feature in  SharePoint 2013. The new Analytics Processing Component in SharePoint Server 2013 runs different analytics jobs to analyze content in the search index and user actions that were performed on a site to identify items that users perceive as more relevant than others.

By including these recommendations on a page, you can guide users to other content that may be relevant for them. You can do this by adding Recommended Items and Popular Items Web Parts in the SharePoint 2013 site. You can configure the Web Part to display recommendations for the document or item that a user is viewing. For example, these recommendations can be displayed under the heading Users who viewed this document also viewed.


You can use the Popular Items Web Part to display the most popular items that satisfy a set of criteria. For example, these recommendations can be displayed under the heading Most popular items in this category.

The search recommendations framework works in the following way:

• User actions produce usage events. When users interact with a SharePoint Server 2013 website — for example, when they click a link, press a button, or view a document — their actions are stored as usage events.
  
• Usage events are counted and analyzed. The recommendations algorithm in the Analytics Processing Component counts and analyzes the usage events.