Google added Subscribe Links to Custom Search Results pages, You’ll notice at the bottom of the preferences page a list of subscriptions and a link to a directory of subscriptions. Each Subscribed Link matches some of your queries (for example, queries about weather, nutrition, traffic) and shows information extracted from a database. It's like a Google OneBox created by third-parties, but you can decide if you want to see it and there's always an option to unsubscribe.
Google, Search, Web Search, Search Result, Subscribed Links, New Features, Google Co-op
Subscribed Links offer a way for you to add information from additional sources or services to your Google search results. When you search using queries that match your Subscribed Link, information from the provider will appear in your search results.
Using Subscribed Links, you can add information created by providers you trust to your Google search results pages. Whenever you search on Google in an area of their expertise, you'll see a custom result from those providers in your search results. To view a list of available Subscribed Links with example queries, visit the Subscribed Links directory.[Google FAQ]