Verizon announced Thursday morning that its net income increased 15.8% to $1.95 billion in the first quarter of 2013.

In particular, the quarter was a blockbuster period for smartphone sales - sales, once again, led by Apple's iPhone. Of the 7.2 million smartphones activated on Verizon's network during Q1, the iPhone accounted for 4 million of them.

Not surprisingly, approximately 50% of the iPhones activated were 4G LTE devices. The carrier's 4G LTE service is available in 491 markets in the U.S. today.

All told, the nation's largest wireless carrier added 677,000 post-paid (or contract) customers for the first quarter.

"Verizon is off to an excellent start in 2013, said Verizon CEO Lowell McAdam. "Our strategic investments in wireless, wireline and global networks have given us the platforms to sustain momentum and take advantage of growth opportunities in key markets for broadband, video and cloud services. With ongoing improvements in operating efficiency, we expect continued growth in free cash flow and earnings as we move through the year."

Source: Verizon (via WSJ)