Google Custom Search was built using the company’s core search technology, and has the ability to prioritize or restrict search results based on websites and pages that the webmaster specifies, and which can be tailored to reflect the site’s point of view or area of expertise.
“As you might imagine, it’s a simple and straightforward product to use and understand,” Shashi Seth and R.V. Guha of Google’s Co-op team said on the Google blog. “In a matter of minutes you can create a search engine that reflects your knowledge and interests; looks and feels like your own; and, if you choose, you can make money from the traffic you receive through Google's AdSense program.”
AdSense functions the same as it does on Google’s mainstream search engine; contextually relevant advertising is displayed along with search results, and pays web publishers a share of all revenue generated from those ads.
Among its advanced features, the new search engine includes “the ability for web publishers to invite friends and community members to add to and help build the search engine.” Contributors can add additional sites to be included or excluded in the Custom Search Engine and annotate them.
Additionally, web publishers can specify the websites that are displayed when a user searches for certain terms. The choice sites and pages can stand as the sole results, or they can be prioritized among the other sources that Google indexes.
“I do think that this launch will kick off a lot of opportunity that not everyone will see or understand at first,” Google’s Matt Cutts said. “For example, the first person to make a truly kick-butt search engine about biking will likely start to attract volunteers and traction and first-mover attention, and could very well become the authority search for that niche.”