Massively succesful social gaming company Zynga (FarmVille, CityVille) is ramping up for its initial public offering in the coming weeks, but a lack of data related to user churn may keep investors at bay.

That's according to Take-Two CEO Strauss Zelnick, spoke at length about the company at the Reuters Global Media Summit on Tuesday.

"They churn quite quickly and they get new customers. That is their model," he said.

"I think they have disclosure issues, I think you are seeing their acquisition costs go up, marketing costs go up and they have very high churn."

According to Zelnick, the company needs to provide investors with more details on its user churn in order to give a clearer picture of its financial future, saying that the company "hasn't gone public yet because their metrics are sketchy."