For years, Activision has lived on top of the mountain, with Call of Duty sales setting retail records year-over-year. This year, the franchise’s supremacy is challenged by Grand Theft Auto V. It will be interesting to see which ends up on top, but Activision is off to a strong start.

In an announcement this morning, Activision has announced $1 billion in Call of Duty: Ghosts sell-in. These are shipments sent to retail, and may not reflect units sold to consumers.

Additionally, Activision reports that average player sessions are higher than Black Ops II or Modern Warfare 3 were in their first 24 hours. Additionally, Gamestop (disclosure: Game Informer’s parent) reports that Call of Duty: Ghosts is the most pre-ordered next-generation title.

Our Take
It is too early to compare Call of Duty and Grand Theft Auto sales. We know that GTAV sold-through (to customers) at the $1 billion level by day three, however that confirmation didn’t come until Take-Two’s quarterly financial report.

What Activision is reporting is “sell-in.” Those are revenues generated by payments made by retailers (not by customers). Depending on sales at the counter, that number might be revised down, as sell-in agreements typically include provisions for retailers to return a portion of unsold stock at a pre-arranged cutoff point.

It also certainly helps that Call of Duty: Ghosts is launching on six platforms (Xbox One, Xbox 360, PlayStation 4, PlayStation 3, Wii U, and PC) to GTA’s two. Also, if Activision shipped its next-gen copies to retail already, those numbers are included even though the consoles themselves aren’t yet on sale.

The numbers are certainly impressive, but until some more time passes, we won’t know whether Call of Duty retains its crown this year. Regardless, more huge releases are good news for the industry.