Ubisoft’s Watch Dogs blockbuster has sold more than 9 million copies to date, according to an earnings release today from the French game publisher. That’s about $540 million at retail, and it’s an outstanding performance for a game based on a new intellectual property.

And that’s a big endorsement for Ubisoft’s strategy of creating new franchises that set itself apart from the pack in the video game business, where derivative titles are much too common.

In Watch Dogs, you assume the role of Aiden Pearce, a vigilante hacker whose criminal past led to a violent family tragedy. As Pearce, you can monitor and hack enemies, manipulating everything connected to the future city of Chicago’s Central Operating System (ctOS), which controls every piece of the city’s infrastructure and holds information on all its residents. You can control securities cameras, listen in on smartphone calls, or hack ATMs — pretty much do everything that hackers have been doing to us in real life. You can use your skills for good or evil.

Yves Guillemot, the chief executive of Ubisoft, said in a statement that the company saw a very strong first half, with sales up 65 percent from a year earlier, thanks to Watch Dogs sales. Watch Dogs sold more than 4 million in its first week after its release on May 27.

In a conference call, Guillemot said Watch Dogs should exceed 10 million units sold by year end, and he said “great things” are planned for the Watch Dog franchise in the future.

The connection to today’s headlines, like Edward Snowden’s revelations about massive spying by the National Security Agency, made the story and message of Watch Dogs relevant, timely, and intriguing. It raised questions about vigilantism, the ethics of voyeurs who eavesdrop on the private lives of others, and just how much data can be collected about a person and used against them. And it was pretty fun to play in its open world for dozens of hours. It has a score of 80 out of 100 on the PlayStation 4 on Metacritic, the review score aggregator. Our review put the score at 85 out of 100.