So, a big company with a strong brand that a lot of people recognize did a study to see how effective their PPC ads are. During the course of this study, they discovered that buying these ads didn't cause an appreciable increase in sales...<p>Consumers go through stages until they finally adopt your product (if they ever do). In the beginning, they have never heard of you, so they certainly can't become customers. Then, they gain some basic awareness that you exist. Once they gain some basic awareness, some may choose to learn more about you. And, after they gain more knowledge, some people will choose to make a trial purchase. Finally, if your product/service is good (and the experience is good), some consumers will choose to adopt your service - they will become long term customers (and a good source of word of mouth)...<p>I'd argue that PPC is great for awareness, knowledge and even (maybe) convincing people to make a trial purchase. But after that, the company itself has to provide a good service. Further, it's rather obvious that once the marketplace knows that you exist and knows a bit about you, you won't gain as much from this type of advertising...