Цитата другой цитаты, опубликованной на форуме SearchEngines.ru, автор оригинала неизвестен:

1. My preferred link location is top left of pages. Links at bottom pf pages have least value.
2. Using the term "sponsorship", "sponsors", "advertisers", etc in body text makes the links nearly worthless per Google algorithm.
3. If you need to identify sponsors or advertisers, use a graphic image and make sure links are in the body of pages.
4. Allow up to 30 characters of anchor text.
5. Do not accept any customers with Page Rank of zero.

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Upper left and top of page placements are preferred, followed by left vertical placments, center of page and lower page placements. Bottom of page placements are given the least logrithmic weight, and are therefore least desirable to knowledgable buyers. In all instances, qualifying "sponsors", "advertisers", etc., should be done only with a gif or
similar graphic image, as the google algorithm, in particular, gives negligible value to links that follow.

Finally, outbound links essentially "dilute" the mathmatical value of competing links, so limits should be placed to maximize value to paying customers. 10 to 15 outbound links maximum is a good practice, with perhaps 30 characters maximum of anchor text. Refuse any sites that either have page rank zero, or show obvious signs of link farming or cross linking.
Who you link to is very important, strategically speaking.