Know-How Exchange : Student Questions

I live in Slovenia and in our country (as well as in the entire EU) product placement isn't banned but advertorials are. I believe both methods work the same way. Consumers of the media content or movies aren't paying attention to the products (services) used because they are too (usually) involved in the plot. I understand that there is a big problem with subliminal messages - the treshold is different from person to person and what is subliminal for one person may not be for the other + do they even work? - but I do think that majority of product placement works in this manner. My teachers tell me that if the product isn't obviously on display (or other product placement techniques) we can't talk of product placement. I disagree. The most powerfull product placement in my opinion is the one that is subliminal (I do not mean quick frames involving products but something that a carefull movie analysis would notice). This question is important for my diploma so I would appreciate it very much if you could discuss this subject - your views, maybe if you know any expert articles on the subject...directions for me - how to deal with the subject and to the best diploma ever on product placement ;P Thank you!