Now keep in mind that the following comment is purely speculation, but I feel that not only will NoFollow links NOT hurt you, they will HELP you. I have heard about people getting thrown to the sandbox for not mixing in a few nofollow links, etc. The idea I like to keep fresh in my head when link building is to think like an organic, living creature and not try to think like an algorithm. If I see a great niche site that only has nofollow links available, I'll still submit or ask for placement because I want to make absolutely sure that Google knows I'm playing by the rules & manually submitting everything to reputable places. That's just my opinion - interpret as you see fit!
Nofollow links can't hurt your site. Think of it this way - nofollow links may have no SEO benefits but they can be a good source of traffic.
Nofollow backlinks coming into your site probably can't hurt you at all. However, lately I've been seeing lots of sites and blogs using the nofollow tag in all their outbound links. I assume this is an attempt to "conserve" pagerank and not let it leave a site/domain. I doubt that this is a good idea and it's one case where nofollow can probably hurt you (mainly because it looks so unnatural).
In my experience, Google does give some weight to nofollow links. People started putting nofollow on all of their outgoing links to try to help keep all of the page rank within their own site. This basically means Google shot themselves in the foot with this idea, so now they do give weight to nofollow links, but they may run it through some additional algorithms. For example, a single nofollow link from wikipedia will probably help you, but 5,000 nofollow links from the comments of unknown blogs probably won't.
I agree with geester. Having both actually helps. I outsource a lot and do a variety of linking. Some follow and some no-follow.
How do you think nofollow links help ? With google I mean - disregarding the other search engines (most of which I believe do honour nofollow). Google does not use that link to increase the PR of the page linked to. Bizarrely (given that its called nofollow) googlebot does follow the link and will go on to other pages that your page links to. I cant see how nofollow links can hurt though.
no fallow links never hurt your site . only google fallow rule no fallow and do fallow . but yahoo and other search engine fallow all the links.
Yes they always frustrate me because they don't helps in achieving backliks. But I used them some time when I require only traffic to my website. they helpful only to built a traffic.
You need a good varity of everyting. -Nofollow -Dofollow -Low Pr -High Pr -Directories -Ping -Social Networking -ect Dont just do one and think your going to be ranked number 1. "SEO is a science & an art"
This is not exactly true. Nofollow links do help in search engines other than google, but do not damage in google or any other SEs
No-follow links don't actually hurt you nor improve anything towards your website, but they do make your link building process look more natural to Google.
NOfollow link is still better than no link at all. Obviously having some dofollow from highly ranked website is good. Too bad such websites belong to the minority.
It doesn't hurt anything, they are just useless for serp but they can bring you traffic so i use them all, a backlink always is a backlink!