Microsoft has finally brought Nokia's device unit on board, about seven months after announcing it was planning to acquire the operation that once dominated the cell phone market. It is now up to Microsoft's new CEO, Satya Nadella, to make use of the business, which Microsoft ended up paying more than $7.5 billion for. Nokia's mobile devices will become the hardware arm of Microsoft's "mobile first and cloud first" approach that is the cornerstone of Nadella's strategy. With Nokia's mobile assets now part of the company, Microsoft is the second-largest maker of mobile devices, with about 14% of the market, according to IDC. At the moment Samsung Electronics and Apple grab almost all the profit in the market.