AT&T announced today that it will buy T-Mobile from Deutche Telekom for $39 billion in both cash and stock. This is one of the biggest mergers in the United States since the beginning of the financial crisis. Not will this deal dramatically boost AT&T’s 4G expansion efforts, but it will add an additional 46.5 million customers to the telecom giant. On top of the custom base and the 4G, T-Mobile was one of the leading telecoms to carry Android smartphones, which will now help contribute directly to AT&T’s bottom line.