The growth should ease investor concern that broadband is slowing and shows why much of the company's capital is going toward network upgrades. It's now the biggest U.S. provider of gigabit speeds.
The pay-TV business remains tough, with video subscribers shrinking as more U.S. customers go for cheaper options such as AT&T's DirecTV Now. The U.S. video losses are a reminder why Comcast is paying $39 billion for Sky Plc—a pay-TV company in Europe, where cord-cutting isn't so prevalent.
Comcast shares were up as much as 6.3 percent to $36.28 on Thursday, the biggest intraday gain since February 2013. The stock had been down 15 percent this year before the results, compared with a decline of less than 1 percent for the S&P 500. Concerns that Comcast is paying too much for Sky have weighed on the stock.