As search engine rules are generally unwritten, it is tempting for some search engine optimization services to bend or occasionally break them.
Your website’s ranking on search engine results pages (SERPs) is determined by a number of things. When web crawlers, or ‘spiders’, visit your site they will index and rank it on a number of factors. One of the most important criteria that are judged is that the content your page relates directly to the page’s content. After all, a search engine’s reputation would be tarnished if it directed its users to sites that aren’t relevant to their search criteria. Even worse, they could unwittingly direct a user to a phishing scam or a page swamped with viruses.
The practise of including spurious meta tags and repeating unrelated keywords to increase traffic to a site is known as ‘spamdexing’, and is something that reputable SEO services would advise you steer well clear of. It has driven the development of sophisticated web crawlers designed to combat it, and it can incur punitive measures such as reducing a page’s rankings or eliminating it from their lists altogether.
Other methods were developed to fool web crawlers. Low quality web pages, known as ‘gateway’ or ‘doorway’ pages, usually contain little in the way of content but are stuffed with similar keywords and phrases. They are designed to rank highly on SERPs but offer no information to visitors, save for links to other sites. Many internet search engines devote a huge amount of resources to combat keyword spamming.