.........sites that have too many links to other sites which have nothing in common with their subject matter?
Like if a wallpaper site carries links to, say, an educational site or something.
Emphatically YES>
Google this topic for more...
Some sites will use automatically generated pages that all point back to a page to try to elevate page rank... google penalizes you for this.
For meta keywords, missing them loses you points, and having too many hurts your score even more, again google it to find specifics.
Your sites "page rank" is calculated by the page rank of other sites that refer back to your site. If many high ranking site link to you... your getting up there.. if lots of low rank sites refer to you, you will be ranked much lower.
There are some other factors in play, (DMOZ) and perhaps sites from different unrelated categories might not count for as much as those from the same categories.
