The job of a good SEO is to help make sure that the web page is useful for the visitors and that the content of the page is good useful content and organized well.
SEO is as much about what not to do as it is about what to do. There are lots of methods that were used in the past to earn a higher rank on search engines that are now considered Spamming. These spamming techniques will not only prevent you from gaining a good listing, but could get your site completely removed from the search engines.
Recently, doorway pages have made headlines as a form of spam. BMW was delisted from google for using doorway pages, and in an unusual move, Google announced that they were removed from the listing for this reason. This was the first time the Google had publicly announced a delisting. The next week another company was also announced as being delisted for the same reasons.
Let's examing the problem and what not to do. Doorway pages are not the same as multiple domain names. It appears to be fine to have many different domain names created that all point to the same page, as long as you want to pay for the names and deal with maintaining them. A doorway page, is another webpage that is rich in keyword content. If I were to create one for SEO it would just be a list of SEO keywords over and over with no real content and a link for a visitor to click on to get to the real content. This kind of a spamming technique will get a website in trouble. Anymore most SEOs know that this is the case and will not do it. However, there are still some unscrupulous SEOs that will try to do this and push the envelope on how much they can get away with before it's considered spamming.
We consider doorway pages to be spamming. It is not a technique that we will use to increase a web sites ranking. We do believe that each keyword should have a content page devoted to it that offers up good content for the visitor to get information from related to that keyword, but we will not create doorway pages for a site.