When the Lumia 920 was announced in September 2012, it was seen by the press as the first high-end Windows Phone that could challenge rivals due to its advanced feature set. Elop said that the positive reaction to it had created a sense of hope and optimism in the company. The company was also making gains in developing countries with its Asha series, which were selling strongly. Although Nokia's smartphone sales and market share greatly increased throughout 2013, including in the North American market, it was still not enough to avoid financial losses. Ollila stepped down as chairman on 4 May 2012 and was replaced by Risto Siilasmaa.