As a general rule, most sites do not need to be enhanced with gateway or doorway pages. This is because a good web site will naturally contain content that uses relevant keyword phrases that potential customers will relate to. This is the same language that will be typed into a search engine box. To put it quite succinctly, if you have quality content on there already you dont need any extra pages submitted by an SEO professional or different content submitted to several search engines to cover your bases.
Usually the matter of gateway or doorway pages comes up for a webmaster that has a site that is overly visual. Web masters that are too cheap or too lazy to hire or write their content also run into this problem. The answer to the dilemma of not having enough content on a site is to add more content, not hire someone to add additional pages from another source to point to your site. Also optimizing your site yourself is often cheaper than hiring an SEO professional to enhance your site with doorway or gateway pages for you. The bottom line here is that adding quality home grown readable content to your site is the best way to increase your search engine popularity and...