Take-Two CEO Strauss Zelnick revealed at a recent conference that Grand Theft Auto 4 has shipped over 22 million units. Gamasutra listened in on ThinkEquity's Growth conference, where the executive noted that the latest installment surpassed the 21.5 million shipped by GTA: San Andreas, with the franchise reaching 114 million shipped since 1997.

Zelnick also discussed how downloadable content can limit rapid used sales for new titles, a tactic the developer experimented with for GTA IV but got exceedingly good at with Red Dead Redemption. He said that once core development is done, doing the development for DLC in a high-quality way is a lot easier and quicker.

"At the time we put out Red Dead Redemption in May, we didn't even have a fantasy that we'd be putting out a zombie title [the Undead Nightmare DLC] for Halloween. But we [did], as it happens." Red Dead Redemption has shipped 12.5 million units in a little over a year.

This article was originally published on Joystiq.

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