Most advertisements are trying to persuade a viewer of something. What is interesting is that many advertisements are not necessarily trying to convince you to buy a product. The advertiser is trying to create specific feelings within a viewer so that person better remembers the company or product. When that person then needs a product in that category, they will likely choose the product that created those specific feelings. For example, beer commercials tends to show people having a fun time while happening to hold the product. An association is made in the viewer. That product equals fun times.
Advertisers create those images and feelings by using special camera techniques. Often close ups are used to trick the viewer into thinking the product is larger. Food ads are extremely guilty of this. Special lighting is often used as well, and it is easily identified when you are looking for it. It is not possible for a person to be outside and front lit and back lit at the same time. Other times the ad will show the product with additional accessories. Car companies are guilty of doing this with their products, and children's toy ads are also guilty of this. Often, the product will always be shown with happy people who also tend to be attractive. Anything Disney does this. Another trick is to show the product without people in the frame in order to trick your mind into assuming something is a particular size.
Advertisements also make use of logical fallacies like what I call the "weasel word" technique. Telling someone that the product gets your dishes virtually clean is an example of a weasel word claim. Virtually is subjective as well as not completely clean. Another logical claim technique is to leave the claim unfinished. Saying something is 222% quieter is an unfinished claim, because it doesn't say what the product is quieter than.