Sub domain on root domain

[dror999]

Hello, 
I have a question that I can't find a good answer on. 
I have a site, actually a "portal"/ "directory" for service providers. 
Now, for start, we opened every service provider own page on our site, but now we get a lot of applications from those providers that thy want sites from their own. 
We want to make every service provider his own site, but on sub domain url. ( they don’t mind… its ok for them) 
So, my site is www.exaple.com 
There site will be: provider.exaple.com 
Now I have two questions: 
1. can it harm my site in SEO? 
2. if one from those sub domain , punished by google because is owner do "black hat seo" , how it will affect the rood domin? It can make the root domain to get punished? 
Thanks!!

[Everett]

Federico brought up some good points when he suggested sub-directories above, but I'd go with sub-domains in this case. If a service provider can't figure out how to build their own website they are unlikely to get any decent links, let alone one from CNN. Policing them all would be expensive, possibly even unscaleable for the business model.

I think the use of subdomains as outlined in his original question would be one of the few proper reasons to have them.

Just make sure you verify each and every one of them in GWT so you know if/when any "manual actions" or important messages come through from Google.

Getting SEOs to agree on sub-domain Vs sub-directory Vs separate TLD can be like trying to herd cats sometimes. That's just the way it is.

[FedeEinhorn]

Nope, that post is completely wrong my friend. Besides being from 2011 or even earlier, the writer probably misunderstood to how Google handles external/internal links in WMT.

What is confirmed is that www.domain.com and other.domain.com ARE different domains and a penalty to other.domain.com DOES NOT affect www.domain.com. Otherwise, all blogspot, wordpress.com and others should be penalized by now.

[BlueprintMarketing]

That is how it used to be now it is different

http://www.organicseoconsultant.com/subdomain-spam-eliminated-by-google/

Google is treating the domain as one domian

[FedeEinhorn]

The way you are thinking of going has its pros and cons.

As subdomains are treated like different domains, a penalized subdomain won't affect your root domain. But neither will be the GOOD thinks that a subdomain may get.

Suppose one of your service providers gets a "super-cool" backlink from an outside source, say CNN links to it. Then all that juice will only go to that provider, you, the root domain, don't get ANY benefit from it, (just like when that subdomain gets a penalty, you don't get it).

Now, the way I would go instead, is simpler, plus you can benefit for any pagerank flowing to your root domain: domain.com/provider then you simply monitor your "provider" and if you detect any black hat SEO, just penalize them yourself by having their site removed (make sure you write a good TERMS OF SERVICE to explain all the rules). So, if any provider gets a penalty, you just remove their site and a 404 code return will be enough, as links to 404s are not flowing pagerank to your site.

Hope that helps!

[BlueprintMarketing]

your questions or

1. can it harm my site in SEO? YES

2. if one from those sub domain , punished by google because is owner do "black hat seo" , how it will affect the rood domin? It can make the root domain to get punished? 
Thanks!!

Absolutely you're talking about giving people access to your website essentially. Or your domain to be more granular. Google and moreover Moz have domain trust rankings and if somebody is doing black hat SEO such as building links that are from link farms or penalized websites to your subdomain which is still on your company's domain. It will affect your overall domain trust and rank

What you have to think about it is your letting these people control a part of your website. If they do things that are not kosher with Google then you will pay the price.

Sorry for the short answer to the top question I think I answered both questions in the 2nd answer.

I would use a .org , .net or .co if you are going to allow people to build something on your network don't give them access to your domain.

If they did all positive things it would help you obviously. However I don't know what you think these people's intentions are going to be.

I hope I was of help,

Thomas