Twitter management opened the company’s inaugural developer conference in San Francisco yesterday by revealing some surprising usage statistics and unveiling more details on its new plans to generate serious revenue.  Co-founder Biz Stone said in his keynote that the microblogging service has almost 106 million registered users and continues to grow by 300,000 users a day; far bigger than analyst estimates. It has 180 million unique visitors a month, its users send 55 million new tweets daily, and the company receives 600 million search queries every day. The company also now has 170 employees, up from around 45 last May.

Meanwhile, COO Dick Costolo said Twitter plans to split advertising revenues equally with smartphone and Web partners that account for most of the micro-blogging service’s traffic. Dow Jones Newswires notes that Costolo’s comments were aimed at scores of syndication partners like TweetDeck or DigiTweet that let users send and read tweets wherever they choose. Such partners account for about 75 percent of the service’s traffic. Costolo’s comments came a day after Twitter announced its ‘Promoted Tweets’ ad business, enabling marketers to pay to make sure their tweets appear as the first result whenever a user conducts a Twitter search.