It’s a little over five months since we launched the Bing Custom Search for general availability, and we're happy to see a considerable number of websites around the world that are now powered by Bing Custom Search. You can use the Bing Custom Search offering for either powering your site search or building the vertical search experience through multiple relevant domains.
Bing Custom Search is an easy-to-use, ad-free search solution that enables users to build a search experience and query content on their specific site, or across a hand-picked set of websites or domains. To help users surface the results they want, Bing Custom Search provides a simple web interface where users can control ranking specifics and pin or block responses to suit their needs.
Read about it in the Azure blog.