Call of Duty: Black Ops 4, the latest game in the franchise, saw worldwide sales top $500 million in the first three days, according to Activision (ATVI). For comparison, last year’s Call of Duty: WW II hit $1 billion in sales, but only after it had been on the market 47 days.

Grand Theft Auto V remains the industry’s fastest selling (and all time selling) title, earning $1 billion in its first three days.

Beyond the notable sales numbers, though, Black Ops 4 also set franchise records for most combined players, average hours per player and total number of hours played in this console generation.

That’s significant as successful launches aren’t enough to dub a game a success these days. Player engagement has become a key bellwether among publishers as the more invested a player is in a title emotionally, the more likely they are to purchase downloadable content in the months to come, increasing the per-title margin.

More importantly, players who are hooked on Call of Duty are spending less time on Fortnite, which has grown into a juggernaut since the last Call of Duty release, bringing in an average of up to $2 million per day. To counter that, Black Ops 4 ditched the single player campaign that has been a hallmark of the series. Instead, the game focuses entirely on multiplayer action, including a mode called “Blackout,” which follows the same Battle Royale rules found in Fortnite. (Players are dropped into an ever-shrinking area, where the last one alive wins the game.)

The strategy seems to be working. Earlier this week, Activision announced digital sales of Black Ops 4 had set a company record, as well as sales records on both the Sony PlayStation and Microsoft Xbox digital storefronts.