Experian Marketing Services has released some findings regarding search trends in the U.S. in 2012, ranking Facebook as the top search term for the fourth year.

According to the firm's findings, Facebook accounted for 4.3 percent of all searches in 2012, marking a 33 percent increase from the previous year.

"Experian Marketing Services analyzed the top 1,000 search terms from Hitwise data for 2012, and Facebook was the top-searched term overall in the US. This is the fourth year that the social networking Website has been the top search term overall," noted the firm.

Four variations of the term "facebook" ranked among the top 10 terms and accounted for 5.62 percent of all U.S. searches overall, marking a 27 percent increase from 2011. When it comes to the top 10 terms, the top two remained the same: "facebook" ranked top, and "youtube" came in on the second spot.

The "craigslist" search term moved up one spot, climbing from the fourth position in 2011 to the third one in 2012. "facebook login" was the fourth most-searched for term this year, followed by "facebook.com" and "yahoo" on the fifth and sixth positions, respectively. Meanwhile, 2012 also marked the first time the search term "amazon" climbed into the top 10 search terms.

The firm's analysis of the search terms found that social networking-related terms dominated the results, making up 6.03 percent of the top 50 searches. Compared with the previous year, this year's 6.03 percent marks a 44 percent increase.

Combined search terms for Facebook (such as "facebook", "facebook login" and "facebook.com") accounted for 5.84 percent of all searches in the U.S. among the top 50 terms, which reflects a 27 percent increase compared with 2011.

YouTube search terms climbed 23 percent from 2011 and reached 1.67 percent, while Google terms, including YouTube accounted for 1.91 percent - a 20 percent increase compared with the previous year. Yahoo terms rose 34 percent to 0.79 percent.

"Navigational searches continue to dominate the top search results as users continue to visit their favorite sites via search engines instead of directly entering a web address into their browser URL bar," said Bill Tancer, Experian Marketing Services' General Manager of Global Search.

"Single-word searches grew 16 percent in 2012 as a result of continued reliance on search engine's suggested results. Other top 2012 searches reflected the ongoing infatuation with celebrities online."