wheel - 12:17 pm on Nov 15, 2007 (gmt 0)

I don't think anyone is likely to come forward with proof. However I'm sure there's emperical evidence that a .edu or two can really help boost rankings.

I don't build backlinks because of pagerank, I build backlinks for 'trust'. Sites that link to me pass 'trust' to me. How much trust they pass to me is based on how much 'trust' they have passed to them as a result of their backlinks.

All things being equal, the same backlinks to a .edu or a .com I would think they're the same. In fact I believe matt cutts publicly commented that this was the case (my memory is horrible, I hope I'm not putting words in his mouth).

The only reason .edu's are looked at is because they're an easy focal point for getting that trust. You know that in most cases a .edu link is going to carry that trust to pass along to you, just by nature of the site owner. That being said, I have a number of backlinks that I value far more than any .edu I've ever recieved. One's actually a PR2 but I'd lose a .edu before I wanted to lose that one.