Over the last few decades, there have been more chances to advertise on TV because of changes in technology like cable and satellite, the rise of commercial TV, and the increase in the number of TV channels. Consumers are getting more and more willing to pay attention to TV ads every day.
Advertising may be one of the hardest parts of the marketing mix to predict because it's so tied to culture and depends on things like language, values, lifestyle, media habits, and so on.
Every advertiser wants to know if their ads are causing people to buy things.
In a perfect world, a quick and significant rise in sales would be the best sign that advertising is effective and working. In the real world, it is hard to find such a clear link between a cause and an effect. Even harder, if not impossible is to agree on a definition of "effective advertising." For some advertisers, effective advertising might just mean making more people aware of their brands. Other advertisers, on the other hand, will have higher expectations and stricter ways to measure success. For some, the point of an advertising campaign could be to make people feel better about the brand.