Not all search engines are equally strict about spam. That is why there is an inappropriate amount of fear over the penalties of spamming. Another can consider tricks that are perfectly acceptable for one search engine as spam.

In some cases, some engines refuse to index pages believed to contain spam, while others index pages, but rank the pages lower. Another option to the search engine is banning the whole site.

Many web masters fear that they may spam the engines without their knowledge and then have their entire site banned from the engines forever. However, this just doesn't happen that easily! The people who run the search engines know that one can be a perfectly legitimate and honest web site owner who, because of the nature of his web site, has pages that appear to be spam to the search engine.

Search engines know that it is difficult to get to know exactly who is spamming and who happens to be in the spam zone by mistake. Therefore, they do not generally ban the entire site from their search engine just because some of the pages of a particular site look like spam. They only penalize the rankings of the offending pages. Any non-offending page is not penalized. Only in the extreme cases, a search engine will ban an entire site.

For example, if a web site spams aggressively and goes against the search engines' recommendations and floods their engine with spam pages, then it will receive a backlash in the form of entire web site ban. Some engines, like HotBot, do not have a lifetime ban policy on spammers. As long as one is not an intentional and aggressive spammer, one should not have to worry about the entire site being penalized or banned from the engines. Only the offending pages will be penalized in ranking.

Also on some search engines, some pages, although found to be using some of the search engine spam techniques, are ranked high. Actually, these are old pages - some are several years old. Had these pages been submitted today, they would have been scored low, or rejected.

Classification of search engine Spam techniques

How Google Search Engine Reacts to Spamming

How Inktomi Search Engine Reacts to Spamming

Just say NO to Search Engine Spamming