I noticed the recent launch of the Erati network led by David Krug.  Erati currently is a list of 7 blogs that are all subdomains of Erati.com. 

They have titles such as:

• biz.erati
• blog.erati
• glitt.erati
• tech.erati

(I would worry about tech.erati.  It seems too close to technorati.)

I hope things go well for David and Matt and the rest of the team with Erati and their sister network, BlogMedia Network.

When we planning out our network, we had a long discussion about whether we wanted to be a tightly branded network and use subdomains as part of the branding, or have each blog have more of its own identity.  We were all familiar with the subdomain model of About.com.

At first, I really argued for the subdomain model, but Hal laid out a convincing argument that allowing each blog to have its independent identity would be a stronger model.  Independent author, unique voice, unique masthead design.  What we would have the same template, we would have the Know More Media logo to the right of the masthead area, we would have our own blogroll of network sites in the third column and we would have feeds from selected sites at the bottom of each site.

We felt that we went the middle ground between About and 9Rules.  About was a very strong brand, with every site a subdomain of about, with each page having the same color scheme and same layout.  If you landed on an About page, you knew you were in the About network.  But the individual guides were less prominent and it would be hard to quickly identify what About site you were on. 9rules was at the other extreme.  Each site was very independent, with various designs, templetes, and structures.  There was very little branding on the site to identify the site as part of a network, except the 9rules logo.  We felt we had some commonality with our template and site layout, but each site had its own url, and its own design and attitude.

One lingering question was the SEO impact of a subdomain based network vs a unique URL based network.  About has done so well with search engine rankings in the past with the interlinking that they do with all their sites.  We link to other sites in our network, so we can offer our other blogs to our readers and get cross traffic within the network.  That is our main objective with the interlinking.  However, we do realize that also creates some linking power. We have heard theories that Google discounts the link value from links that come from the same IP neighborhood or from URLs with the same WHOIS information.  We state it clearly, so that Matt Cutts, or any other Googler that might wander across us,  that we are a network, we are not hiding or disclosing that fact, and there is an inherent value to our readers to have links to other sites within our network.  We don't believe we will be penalized by Google for creating natural links between our sites.

So, a question for Matt and David.  Do you think you will see any difference in your SERP ranking because of Erati's subdomain structure or BlogMedia's unique URL structure?