If a website with poor authority in google's eyes links to my site with a nofollow link. Does that harm my websites ranking in Google?
Have you seen a dip in you analytics? Sounds like negative SEO. I'm not sure about the no follow variable though.
Yes. I ran a testcase on this in 2013 using two garbage tester sites. I hit both of them with backlink spam, one had no-follow spam, one had do-follow. Both dropped from page 1 to page 5-7 and started dancing.
HI Libanadam, According to me, over doing or sudden lift in your backlink will cause major damage in your website. As diggity said in his statement " I hit both of them with backlink spam, one had no-follow spam, one had do-follow. Both dropped from page 1 to page 5-7 and started dancing." So getting links is not the matter. But doing it properly and getting relevant links from quality sites is very important.
When I search for backlinks for a website through link:sitename in Google , I could see the pages having no-follow links to my websites as well which means no-follow links are also counted in the link profile.So , yes, I feel that spam or bad no-follow links can affect your link profile and thereby your rankings as well.
I don't agree with you... Sorry, but if Google checks your website and finds 1,000 dofollow backlinks and ZERO nofollow links, it will be almost 99% sure considered as something fishy...
Over optimization is penalized by Google. Also if a low quality website links to you (it can be a link farm or other low site) there is a chance that your site will lose some ranks.
Yes, they can harm. This is my experience with one of my websites. Great website but bad, no relevant links. Google penalized it. Here is a great resource of linkbuilding strategy: http://pointblankseo.com/link-building-strategies
Yes! Dofollow or Nofollow both are harmful and affect your ranking if its come from low quality sites.
People should really stop caring so much about that old nofollow or dofollow metric. It doesn't matter anymore! Google checks both metrics equally.