Many ads are not clicked on by a real person, but a bot, or someone clicking ads as fast as possible because it is their job.
Many comments would be considered "fraudulent" in the same sense, in that they were not authored by a real person, but a bot, or someone writing comments as fast as possible because it is their job.
Many comments would be considered "fraudulent" in the same sense, in that they were not authored by a real person, but a bot, or someone writing comments as fast as possible because it is their job.