advertisment in tv shows

So I was watching Mythbusters on tv earlier today and noticed something interesting. As I was watching, I realized that the computers used on the show were Dell computers. At first I looked at them and just happened to recognize the laptop because it is the same on I own, which happens to be a Dell. After that I was looking a little more closely. They later showed a monitor that is also a Dell and finally they showed another shot of the Dell monitor but this time they actually showed the label on camera and it clearly read Dell. I just wonder if people really choice their product by the advertising on tv. I mean, if people were to continuously see a specific type of product on tv, would more people be inclined to purchase that product? I guess it is a new way of advertising instead of doing commercials.