"Verizon's strong 3Q12 margins may lead some investors to expect AT&T to similarly beat wireless margin expectations, but we believe such a conclusion is unwarranted," notes Yin. In an analysis of what Verizon's earnings mean for the telecom sector, Yin also highlights that strong subscriber additions are likely the result of market share losses by industry also-rans like Sprint ( S ), T-Mobile and MetroPCS ( PCS ). In particular, as Sprint retires its iDEN network, some customers aren't switching onto its CDMA network, according to Yin. In addition, Yin sees Verizon's subscriber gains as an indication T-Mobile lost post-paid market share in the quarter, calculating up to 400,000 network switchers.