Generally speaking, discussing an investment in SEO services with our customers and potential customers can be like discussing their own funeral arrangements - it is something they know they should at some point be thinking about but it they would rather postpone actually considering it's importance and investing funds. While we tend to warn people that any guarantee of SEO success, especially in a short space of time, should raise alarm bells, website owners considering SEO services from reputable companies should be aware that the methods used are transparent and legitimate, and that results are both quantifiable and represent a good Return on Investment (ROI).
The term "Search Engine Optimization" encompasses many possible facets. While some aspects of SEO can seem like the obscure activities of the occult, the fact is that in it's simplest form SEO is about building websites and web pages using tried-and-tested best practises. Low search engine rankings or not being included in search results at all can be the result of simple coding mistakes, poor website structure, the omission of important meta tags, or poor quality code or content. When a website owner is not aware of the importance of these issues, they can adopt a point of view that SEO is an impossible dream, since nothing they seem to do improves their results. An SEO service can correct these errors and improve organic search results considerably.
Once a website and it's pages are structurally optimized for good search engine rankings, the most important factor in further improving rankings is by sign-posting the website as an authority in it's field. This is achieved by garnering high-quality links to the website from other websites that rank highly for the same subject area. Unless employing "Black-Hat" techniques, which should be avoided at all costs, an SEO service will research the best candidates for such incoming links and reach out to them - and both the candidates and resulting links should be transparent to the customer. This process should be combined with the creation of high quality content that will attract naturally occurring links ("link-bait"), such as a useful tool, free download or quiz.
Another way in which an SEO service can help a website's incoming links contribute to it's search engine rankings is by identifying links that are actually harming rankings - Google has begun to penalize websites which they deem to have "artificial" incoming links. Using special tools, a good SEO service will be able to "disavow" such links so that they are ignored by Google's ranking algorithms in future.
A structurally sound website that has many high-quality incoming links from relevant websites will fare well in search engine rankings. However, the volume of traffic a website will receive when it is ranked seventh for a subject area will be vastly different to when it is ranked first or second. Except in some lucky cases, most websites that rank first or second for highly competitive subject areas engage in perpetual SEO activities, which demonstrates the beneficial ROI that can be achieved from SEO over other marketing activities. This is where the real "magic" of SEO comes into play - competitor intelligence.
If a search engine ranks a specific website first for a subject area, there must be a reason for this. Using software, SEO experts will analyze what is unique about such websites, including which other websites link to it, what words are used for each part of it's content structure, how many times specific words are used, how long it's meta tags are and so on. By copying only this formula, and not any aspect of the website itself, the search engine rankings of other websites can be improved. Of course, even using such an approach can not result in a guaranteed search engine ranking - despite what some companies would have you believe, the algorithms used by search engines are not entirely understood by anyone other than the engineers that design them.
If you are thinking about employing an SEO service, a reputable company should be able to easily identify which aspects of their services are applicable to your website, and the actions they intend to take to improve your rankings should be transparent from the start. Furthermore, they should be able to only estimate how your rankings will improve - any guarantee of specific rankings could imply that they intend to use techniques that are frowned upon by Google, which could result in being permanently removed from their results.