1.5 SEO Bad Practice
Some practices are not very helpful to SEO, and others can be downright harmful or illegal. It is wise to avoid any of the bad practices listed in this section:
Graphic headers
Search engines cannot read images, only text, and the top of a page is a valuable place for inserting keywords. If a logo is needed, a hybrid approach should be adopted. In other words, use a graphic logo and a text header. And where ever possible, use the alt and title attributes to include your keywords.
Graphic navigation menu
Again search engines cannot read images. If a graphic menu must be used, then at least use the alt and title attributes with all image links to give the search robots something to read and index.
Script navigation
Search engines cannot read nor execute scripts. Search robots cannot follow script driven links and so parts of a site will not be indexed. If site navigation scripts are used then a regular HTML duplicate navigation should be provided to make them visible to everyone – human visitors and search robots.
Session identifiers
Some sites use session identifiers, meaning each visitor gets a unique session id when they arrive at a site. A search robot will get a new session id too and will consider the pages as new ones whenever it visits.
Subdirectories
If there are under a couple of dozen pages on a website it is best to place them all in the site root directory. Search engines consider such pages to be more important than those sitting in subdirectories.
Redirects
This is where web traffic is redirected from one URL to another, and they make site analysis more difficult for search robots. However, sometimes redirects are necessary if you have moved or renamed a webpage. For example you may have upgraded your web hosting to use PHP, and so pages may now have a .php extension rather than a .html extension, or they may simply have moved to a new folder. To preserve your SEO and pagerank you will need to add some "301 redirects" into something called a htaccess file. This can be written with a simple text editor and sits next to your web files and simply redirects any inbound links looking for your old files to your new files (the code "301" is interpreted as "moved permanently"). This is the safest, most SEO friendly way of redirecting traffic. It can sometimes be avoided though by planning websites out a little more carefully.
Hidden text
Text colour coinciding with background color is seen as a deception by search engines, as it allows unscrupulous developers to stuff pages with keywords without affecting the layout. Although invisible to human visitors, they are completely visible to search robots. This will result in a banning of the site and exclusion from the index of the search engines. It is certainly not worth the risk.
One-pixel links
The use of tiny, almost invisible graphic image links say just one pixel wide and high are seen as an attempt at deception by the search engines, which may lead to a site ban too. Again, it is not worth the risk.
Link farms
Avoid any websites that seem built simply for other site owners to list their sites on. Adding your URL to one of these types of indexes or "link farms" will most likely get it banned too, or at the least, not viewed in a favourable light.