After three and a half years of AT&T (T) exclusivity, the iPhone finally debuted at Verizon (VZ) in February 2011. What happened to Verizon Wireless profitability during the two years of Apple (AAPL) partnership bliss? The results do not exactly dazzle. During the fourth quarter of 2010, the last quarter when Verizon had to somehow make do without the iPhone, the EBITDA earnings margin of Verizon Wireless was 47.5%. During the fourth quarter of 2012, that margin was 41.4%. That’s a decline of 610 basis points, an enormous gap in the carrier business. Selling, General and Administrative expenses ballooned to $5.9 billion last quarter from $4.6 billion over two years. Cost of services and sales exploded to $7.3 billion from $4.8 billion