Google surpassed 72% U.S. market share in December according to the latest numbers from Experian Hitwise. For Google, that represents a slight gain over November’s share of all U.S. searches. Yahoo, Bing, and Ask.com all saw their search share drop from November to December.

In a separate blog post, Hitwise’s Bill Tancer says Bing’s search “success rate” is on the rise — from about 70% in October to 75% now. In the chart below, Yahoo is the yellow line, Google is purple, and Bing is green.

Hitwise defines “success rate” as “the percentage of executed searches that result in a visit to a site other than a main search domain,” and admits that it’s not a perfect way to grade search engines:

“There is one caveat when reading these numbers; search success rate is often influenced by the complexity of the search. Traditionally, portal search engines tend to have more simple navigational and brand related queries in their top searches which are easier to resolve then searches for information.”

With search engines showing more shortcuts and answers in their search results, a successful search isn’t necessarily one that sends the searcher to another web site.

Related Topics: Stats: Hitwise | Stats: Popularity

About The Author: Matt McGee is Search Engine Land's Executive News Editor, responsible for overseeing our daily news coverage. His news career includes time spent in TV, radio, and print journalism. His web career continues to include a small number of SEO and social media consulting clients, as well as regular speaking engagements at marketing events around the U.S. He blogs at Small Business Search Marketing and can be found on Twitter at @MattMcGee and/or on Google Plus. See more articles by Matt McGee