I think that product placement on television is an effective way of advertising. Product placement seems, to me, to resemble subconscious advertising, because the viewer is not necessarily directly informed that they are being advertised to until after they see the product, and whether or not it registers for the consumer that they have witnessed a subtle ad, the image probably more than likely sticks in their head. Its not unexpected becuase the media is always trying for the next best way to advertise to consumers, neither is it significantly wrong when compared to some of the other extremes media has utilized to reach consumers. Its just another example of how media can affect and reach people without many of them knowing.
Product placement also seems like another form of a testimonial of sorts. The only major difference is that the clelebrity or medium is not directly endorsing the product, but rather indirectly, which can sometimes have the same effects, it just depends on who's watching and paying attention.
Teenagers, more than any other age demographic, are porobably more likely to be affected by product placement. Teenagers consume more media and products than any other age group and are more aware of the brands out there. Also, teenagers are at an age where being cool and fitting in are emphasized, and when "cool" is associated with celebrities, clothing, or movies, for example, and celebrities and movies are associated with certain products, then deductive reasoning dictates that teenagers are going to be attracted to the certain products.

ACT Commercial
"cleans gums and kills mouth bacteria" This is a good example of a water is wet claim. There are other brands in the mouthwash category, such as Listerine, which claim to and do the same things.
"helps prevent cavities" and "promotes healthy gums." this is an example of weasel words propaganda with the usage of helps and promotes.
There is use of a testimonial in this commercial using celebrity Christie Brinkley. She is used to further another propaganda device, the Hidden Fears technique. Towards the end of the commercial, Christie asks consumers whether or not they are taking the best care of their smiles, and suggests that shouldn't they be taking the best care of their smiles, as she flashes her pearly whites across the television.

Geico Commercial
the claim "so easy a caveman could do it" appeared numerous times during the commercial; on billboards, on street signs, as a spoken sentence. This idea is being used to appeal to the strivers who want directness in their commercials.
This strategy works because it uses the plain folks appeal; talking down to the masses so as to seem like them. Many consumers like being able to see that the ad has made an attempt to make them feel as though they can obtain the product without any complications, and that they will be successful.
"15 minutes could save you 15% or more on car insurance."