Everybody agrees that broadband music site Pandora is a great service, but is it a great business? We’ll start to see now: The company, which went public in June, had its first earnings call today, reporting second-quarter revenue ($67 million) and profit (2 cents per share) that both exceeded analyst expectations. Ad sales and subscriptions more than doubled compared with last quarter, the company said. Looking ahead, Pandora forecasts estimate-beating revenue of $69.5 million-$72.5 million and even to a loss of 2 cents a share (excluding items) in the current quarter and a loss of 5 cents-7 cents for the year as it figures out how to fight competition from fellow streaming service Spotify, Sirius XM and terrestrial radio and blend commercials into its free model. The stock rose after hours on the news.