LinkedIn didn't use a salt. Hence the easier-than-it-should-have-been password crackfest.

(However, could everyone please stop making random websites encouraging people to type in their passwords from third party sites!)

I suspected that was the answer but this blog post http://blog.linkedin.com/2012/06/06/linkedin-member-password... mentions that they are salting the passwords.

It doesn't, LinkedIn didn't salt the passwords.