Since the development of Search Engine Optimization as a concept, there has been an obvious temptation for some people to try to cheat the system. Because the whole premise of SEO is that keywords create cash, the idea occurred to a lot of people that this could be taken to the extreme, and can best be summed up as: “If they want keyword volume, then we’ll give them keyword volume”. This tends to occur in the shape of website text that contains nothing but keywords (this practice is known as “Keyword Stuffing”). It’s keywords on steroids, and just like using steroids in sport it is still regarded as cheating.
Of course, this means that the website will be scarcely readable, if it is readable at all, but the trick is usually applied as a landing page that immediately redirects you to the site they want you to read. It will happen instantly and you will not see the landing page, but it will have done its job. For the reader it may be little more than an inconvenience, but for other people operating in the same niche, it is cheating nonetheless.
The main reason that tricks like this are a bad idea has only a small amount to do with the fact that it is cheating, and more to do with the consequences when you are found out (…and you will be). In actual fact, it is incredibly limited as an SEO tool because Google and other search engines check for such tricks and will relegate any such site in their rankings – so not only is it dishonest, it is also ineffective.
Although it will take more time and more work, you are better sticking to White-Hat SEO techniques, and avoid being penalized.