San Francisco, June 5 : Linda Yaccarino took over as the new Twitter CEO on Monday, freeing Elon Musk to focus on Tesla and SpaceX, as Twitter's US ad sales plunged 59 per cent in April and the month of May did not look bright either. Yaccarino, former Chairman of Global Advertising and Partnerships at NBC Universal, updated her bio as Twitter CEO on LinkedIn, before welcoming Joe Benarroch at the micro-blogging platform, who worked with her as executive vice president at NBC Universal. "Welcome to the flock, Benarroch, from one bird to the next. Let's get to work @Twitter," she posted. Benarroch said in an internal memo, seen by the Wall Street Journal, that "I start a different professional adventure at Twitter, taking on a role focusing on business operations". "I am looking forward to bringing my experience to Twitter, and to working with the entire team to build Twitter 2.0 together," he added. According to The New York Times, Twitter's US advertising revenue for the five weeks from April 1 to the first week of May was $88 million, down 59 per cent from a year earlier. "In internal forecasts, the company projected that ad sales would keep declining, handing a tough challenge to its new chief executive," the report noted. Yaccarino said last month that she is prepared to build Twitter 2.0 and transform the business together with Musk and millions of platform users. "I've long been inspired by your vision to create a brighter future. I'm excited to help bring this vision to Twitter and transform this business together," she posted on Twitter. "I'm just as committed to the future of this platform. Your feedback is VITAL to that future. I'm here for all of it. Let's keep the conversation going and build Twitter 2.0 together," Yaccarino also commented. Musk is looking forward to working with Yaccarino to transform the platform into X, the everything app, just like China's WeChat. Yaccarino oversaw about 2,000 workers at NBC Universal. Her team generated more than $100 billion in ad sales and entered partnerships with companies, including Apple, Snapchat, BuzzFeed, Twitter and YouTube. /IANS