A study conducted by EEDAR and SMU's Guildhall found trusted media outlets do affect consumers' perception of video games and their willingness to purchase. Joystiq received an advanced copy of the study (releasing publicly next week), that involved 165 qualified participants split into three groups, who were then exposed to high, low and no review scores for Plants vs. Zombies before playing the game. After the 20-minute session, the subjects were offered either a copy of the game or $10. A result of the study was that participants exposed to higher review scores were 100 percent more likely than those exposed to low scores to take a copy of Plants vs. Zombies over the $10 and "85 percent more likely to take the game than the control group." The study concludes that "because nearly twice as many participants in the high review group took the copy ... that the relationship between video game sales and professional review scores are not correlative but causal."

Plants vs. Zombies was chosen because it's "regarded by the gaming community and by critics as a high quality title of broad appeal." The mock reviews used in the study were from five well-known media outlets and participants were told that the aggregate review score they were given was "comprised of 51 professional" outlets. All participants "played the same game, on the same type of computer, in the same environment, for the same amount of time."