Last we heard, Paradox Interactive's publishing deal for Magicka with Arrowhead Games was working out pretty well. This morning, just after a GDC Europe presentation by the niche Swedish publishing house, Paradox CEO Fredrik Wester further added to the game's history of financial success, when he told me that the title has now sold nearly 800,000 units.

"It's gonna pass that [sales milestone] in the next week, week after or so," Wester said. "We're still doing between five and seven thousand a week, so it's a great sales number." He also added that Paradox hopes to pass the one million sales mark by the end of 2011 -- a major achievement for a small team like Arrowhead.

As for the much-loved Vietnam expansion, I wondered if it had achieved the same success that both Paradox and Arrowhead had hoped for. "It's done a few hundred thousand, so the attachment rate is really high," Wester explained.

With those kinds of numbers, it's clear why Paradox is interested in fostering and furthering the relationship with Arrowhead. Back in May, Wester told me that sequels for Magicka are a lock.

This article was originally published on Joystiq.