A big bonus for Bing, although, quoting from Mozilla CEO: It Wasn’t Money — Yahoo Was The Better Strategic Partner For Firefox (Marketing Land), "One bright spot for Google — it remains the Firefox partner in Europe, something the Firefox blog post omitted. That post made clear Yahoo was the new US choice, Yandex the new Russian choice and Baidu the choice in China."
"After six years of generating close to 90 percent of its revenue from referring Firefox browser users to search using Google, Mozilla announced today it is partnering with Yahoo instead.Yahoo Replaces Google as Mozilla Search Partner | Re/code
Mozilla and Google had continued their relationship despite the fact that Google’s Chrome competed directly with Firefox and surpassed its traffic in 2011. The latest three-year deal had Google paying Mozilla some $300 million per year.
Choosing Yahoo was about “choice and independence,” said Mozilla CEO Chris Beard. He noted Firefox users search the Web more than 100 billion times per year."