When I was growing up, never would I of though that the word billion would be used when talking about video game sales. But, nonetheless, here we are. That said, as much as I hate the management over at Activision, Activision’s Call of Duty series has ranked in a total of $3 Billion in retail sales worldwide, according to The NPD Group, Charttrack, GfK and internal Activision estimates.

“Call Of Duty has become one of the greatest entertainment franchises of all time. If you consider the number of hours our audiences are engaged in playing Call of Duty games, it is likely to be one of the most viewed of all entertainment experiences in modern history,” said Activision CEO, Bobby Kotick.

It’s obvious that Activision and Kotick have struck gold; alot of it. However, knowing Activision, we can expect more from the Call of Duty series.

There’s going to be a Dead Space sequel, Electronic Arts even confirmed that there’s going to be another one – that isn’t Dead Space Extraction. And, according to Reuters, the Dead Space sequel is due to hit next year, evidence given by the “advanced state of preparations for Dead Space 2′s development”.

In a Halloween themed feature on horror video game sales, Reuters reported that the Dead Space sequel will be shipping next year. Sadly, there’s isn’t any other details, nor did EA respond happily to the news statement. ”This comment by the Reuters reporter is speculative,” an EA representative told GameSpot. “There is no announcement for a Dead Space sequel (or in this case, prequel) beyond Dead Space Extraction.”

As for the original, Dead Space was widely accepted by critics. However, that didn’t translate into high sales. According to the NPD Group, the game shifted just 9,200 units during its first week at retail in the US. Which, back in may, translated into 1.4 million units worldwide.

Many are wondering just how well Killzone 2 is faring since its release in late February. Well, after Guerilla Games’ title “exceeded our expectations” – which was logged by Sony when reports appeared that the game had sold 500,000 copies in the U.S. – something like this was going to occur.

When anticipating the NPD Group’s monthly sales estimates, Sony replied with hast that their PlayStation 3 exclusive shooter Killzone 2 has sold more than 1 million copies – but not in America alone, worldwide.

SCEA boasted that “approximately 1 in every 3 PS3 titles achieve Metacritic scores of 80 or higher, which affirms PlayStation’s proven track record in delivering rich and relevant entertainment content.”

[Killzone 2 Eclipses 1 Million Sold via GameDaily]