There is a popular newbie SEO article about search engine ranking factors. It is written weighing Google’s tendencies higher than Yahoo’s or MSN’s (and properly so). For example, the age of the TLD is much more important in Google than in Yahoo and almost irrelevant in MSN. Also, the internal linking structure seems to me much more important in Yahoo than in Google or MSN.

I think it goes a bit far on the subject of link spamming:

Whether via automated blog or guestbook spamming, hexcode submissions to site searches or other less nefarious methods, any links garnered via automated or “unnatural” methods or perceived to be obtained thusly by search engines can hurt ranking abilities of TLDs or individual pages.

Any link garnered via “unnatural” methods? That’ a stretch.

Moreover, it does not give enough weight to URL structure to compete in MSN. If Google won’t penalize you and it helps in MSN, why not code your URLs like this:

yoursite.com/keyword-keyword

instead of

yoursite.com/mfdsrep=34523

Several SEO heavyweights Aaron Wall, Danny Sullivan, NickW, or John Battelle don’t use SEFURLs for their blog posts. But that is likely because they were started before it was determined to be a factor . . . (note: Matt Cutts does).