Passive mediums of media have a greater effect on users than more active mediums.

It is a well-known fact that humans are able to absorb massive amounts of information being thrown at them, even if they are not conscious of it. We are constantly exposed to media in many different forms, some passive and some interactive. 
Passive mediums are forms of media that can only be consumed. The biggest and most widely experienced medium of this sort would be the television. Watching TV requires no real effort from the user. We sit, we listen and we watch. Some may watch while eating, others may keep it on as background noise, either way it leaves a significant impact on the viewer. 
More interactive mediums of media are ones that physically engage the viewer along with consumption. A common example of this would be video games. Video games need the constant engagement and response of the viewer in order for the user to understand the content.
It can be conceived that video games have a greater effect on users because they are controlling what they are being exposed to. But I would say that is why television has such a greater effect. Video game users are only exposed to the game itself. They consciously control the moves they will make and they are aware of what is happening. On the other hand television viewers are being effected without being aware of it. They are exposed to hundreds of advertisements, which many try to tune out or ignore. Yet how many times have you caught yourself singing along to a cheesy "freecreditreport.com" jingle? Television plays a much larger part in our lives than we suspect. 
It is important to note that these mediums are not necessarily a direct cause of user actions. But they are more like symptoms to of their actions.

Sources: http://contently.com/strategist/2012/09/06/understanding-active-vs-passive-media-the-road-out-of-marketing-hell/

Pavlik, John V., and Shawn Mcintosh. Converging Media. 3rd ed. New York: Oxford UP, 2011. 445. Print.