IGN

During a session at GDC Europe, Guido Eickmeyer of Deep Silver revealed what he believed to be the secret to Dead Island’s success. It wasn’t the cinematic trailer, though that had an impact. It wasn’t the reviews (Dead Island does not have a stellar Metacritic rating). And it wasn’t the development budget, because Eickmeyer claimed they had nowhere close the amount of money for building and marketing the game that a bigger AAA game publisher would. Instead, he singled out one feature: co-op.

To date, 6500 years of Dead Island have been played cooperatively. This feature, combined with the setting, lots of squishy, shambling enemies and a RPG-like progression structure helped push the game to sell through more than 4 million copies.

Unlike traditional retail game sales, which spike at launch and then fall off the map after a few months, Dead Island sold consistently across a long period of time, said Eickmeyer, which he attributed to word of mouth. He also mentioned Dead Island had a 53% retention rate for add-on content purchases.

Naturally, due to the high sales, we’ll be seeing more of Dead Island. Riptide was recently announced, and chances are, it will also have zombies in it. Hopefully more details will emerge soon.

http://ie.ign.com/articles/2012/08/13/dead-island-over-4-million-copies-sold

Awesome. Dead Island is one of those few console games who sold a lot through word of mouth.

Great sales...but not as high as they should be! This game is awesome, it's like GTA but on a paradise island with zombies...what's not to like? The sequel to this will be huge though, that's for sure

This game was so understock where I lived prices for both Xbox and PS3 were up by at least 20% from usual game prices

Everything is usually better with Zombies, but this game was meh. First Person Mellee combat doe not work yet.

got it on black friday for 30 bucks still havent beat it but working on it.. really been playing it on solo, will try some co-op hopefully with friends and not strangers.