Obstacles to SEO Optimisation

Obstacles to SEO Optimisation:

Embedded JavaScript Navigation:
Search engines prefer external Javascript files to embedded script, which spiders cannot follow.

Frames:
Pages designed using frames (sometimes called iframes) cannot be indexed effectively by a search engine spider.

Tables:
Inappropriate use of tables for design, rather than the use of cascading style sheets (CSS), which use complicated HTML code, thus rendering it more difficult for the spider to crawl. Tables should only be used to display tabular data.

Flash:
Overuse can trip up a spider because a search engine cannot read Flash or Shockwave content.

Splash Pages:
Although they seem like a good idea, they bury the content of the site one level deeper, making it harder for the spider to find the top level pages for indexing.

Complex URLs:
Essentially a spider will not bother to follow a complicated link – http://www.url.com/page.php?id=58fnh3User=%Tim%

Pages Buried More than Three Clicks/Links from the Index Page:
Spiders often ignore pages deeper than three levels down.

Broken Links:
Not only are linked-to pages never found, it is believed that some search engines degrade rankings of sites and pages with broken links.