How Search Engines Define Spam
Long ago, and by this I mean several years ago, it was possible to push just about any page into a top ten ranking with a combination of tricks.
Those days are long since past and the SE's themselves are very aggressive in combating this kind of trickery as tempting as it may be to try to deceive the search engines, your client's site either belongs somewhere in the rankings or it doesn't.
As long as you stick to truly relevant and targeted search terms and don't take on lousy sites, you should find it completely unnecessary to spam the SE.
How Search Engine Define Spam? Every search engine has its own guidelines, but they all boil down to the same thing don't try to trick our users or us.
This is basic to a search engine's survival and they will impose harsh penalties on sites that transgress this simple rule.
Search engine Spam can be broken down into a few broad categories.
I have never met anyone who had any trouble understanding the difference between ordinary search engine optimizations and spam.
Content Spam: This involves any attempt to deceive the SE through the manipulation of on-page content, and could include practices like keywords stuffing, misuse of < meta> tags, misuse of HTML features (< noscript>, < noframe>), or deliberately creating misleading content.
Domain Spam: Domain Spam is the registration of multiple domain names in an attempt to boost rankings.
This may be done in order to obtain multiple directory listing, create cross-links between domains or simply as an attempt to put more pages in the index to increase the odds of having a page ranked.
Link Spam: Link Spam describes the use of any deceptive scheme intended to boost the link popularity or page rank of the page artificially.
Included in this category are tactics such as hiding links from users, hiding links from search engines (hoarding page rank).
Creating artificial domains to manufacturer links, and buying links from unrelated pages.
Redirect Spam: Redirect Spam involves deflecting visitors to a page other than the one that was ranked.
There are many schemes that create doorway pages that rank well, and a variety of techniques are used to redirect the visitor to another page or conceal the ranked content behind a pop-over element.
All constitute Spam.
Cloaking: Cloaking is the worst from of Spam from the SEO perspective.
Cloaking involves the use of a variety of techniques to deliver optimized to the SE's, and different content to human visitors.
All the search engines tell webmasters not to cloak.
Many justifications have been invented fro cloaking, but in practice, it's simply not necessary.