Do bad links to a sub-domain which redirects to our primary domain pass link juice and hurt rankings?

[Shredward]

Sometime in the distant past there existed a blog.domain.com for domain.com.  This was before we started work for domain.com.  During the process of optimizing domain.com we decided to 301 blog.domain.com to www.domain.com.

Recently, we discovered that blog.domain.com actually has a lot of bad links pointing towards it.  By a lot I mean, 5000+.

I am curious to hear people's opinions on the following:

1. Are they passing bad link juice?

2. does Google consider links to a sub-domain being passed through a 301 to be bad links to our primary domain?

3. The best approach to having these links removed?

[kchandler]

1. Are they passing bad link juice?
Yes, if you 301 redirected a website/page you bring over both the good and the bad link equity with it.

2. does Google consider links to a sub-domain being passed through a 301 to be bad links to our primary domain?
Refer to question 1

3. The best approach to having these links removed?
Have you received a unnatural links warning in GWT yet? If not you maybe safe with waiting it out. If you are trying to cut it off before that happens i would start with running a LinkDetox report (only $50 and totally worth it). They will define the toxic links, from there i would disavow them.

Hope this helps!

• Kyle

[Shredward]

Kyle,

Appreciate the response and your insight.  The subdomain was set to 301, which made me nervous about the bad links.  However, there has been no warning in GWMT.  I am curious where the threshold lies for GWMT to flag your link profile.  And if a poor link profile can affect your site's authority before you cross that line in GWMT.

I highly doubt a straight answer exists for that question, but I'd be curious to here yours (and others) experiences with the matter.

Thanks again!