Hello, i heard that .edu links are good for pagerank, but do they need to be .edu or something else like .edu.mx, .edu.au are both good? Thanks.
Personally, I think the main thing that EDU links provide your site is domain trust. Unlike most ranking factors, getting links from trusted domains like a .edu benefits EVERY URL on your site, not just the URL on your site being linked to by the .edu domain. EDU links do NOT pass you any more PR than an equivalent non-EDU link would. How much PR an EDU or non-EDU link passes you is based on the PR of the page linking to your URL and the number of followed outbound links on that page that links to you. PERIOD. However, EDU links to your site (like .GOV and some other types of "trusted" sites) do generally pass you a LOT of domain trust. If you don't understand domain trust, there is a recent SEOmoz Whiteboard Friday Video on Domain Trust and Domain Authority that does a good job of explaining it.
Then how about my second question, are .edu.mx or .edu.au or similar .edu CLD as same as .edu itself? Thanks.
If edu link URL have high PR, then it is helpful for ur website PR, edu links helpful for ranking also
From a PR perspective I totally agree w/ NeuroToxic. I think I said the same thing, only not in Matt Cutt's own words. The questions and answers that he quoted from the Pubcon interview Matt Cutts were strictly in regards to the effect of .gov and .edu links on Page Rank which answered the OPs original question perfectly... There was another question that immediately followed in that same Cutts interview and note Matt Cutt's response: This is a "secret sauce" question... He's implying that there are other ways that .edu and .gov links affect your URL's ranking in the SERPs but he did not want to get into the specifics of how probably because it is something proprietary that distinquishes their ranking algorithm from those of the other engines. Unlike Page Rank for which they have pretty much made the formulas for calculating it public knowledge thru patents and such... how .edu and .gov links affect your rankings in the SERPs are not public knowledge. But many tests have shown that there are other positive side effects of getting these types of links. "Domain Trust" is one of the ranking factors believed to be greatly influenced by these types of links.
Good catch Canonical. The trust issue definitely is a valid argument. Google has openly admitted that they ae now focusing more on website trust factors. A link from an aged, well linked site establishes trust regardless of the PR of the linking page. Most edu's are both aged and well linked. Since not anyone can create a .edu site, they may give a larger trust boost.