I refer here to a multi-site configuration in which several sites/domains share the same Drupal code-base, while each site has its own database. Here I assume that you know how to create a multi-site installation that works well.
See here a screenshot for the Advance Settings of the Drupal Domain Access module.
Here are the absolute best and reliable Link Building Services.
<You can download the picture at the bottom of this blog post.>
The diagram above shows how I have set up the flow between my blog, Twitter, Facebook and Yahoo.
Backlinks is an important element of any SEO strategy. How do you check how many backlinks you have. And how do you see how many different domains link to your site?
You can use the available services from for example Yahoo!. But the problem I see is that you cannot see easily from how many different domains you get backlinks.
The best tool I have found for this is:
I believe you can use it only once per 5 days or so to check the same domain, but that is fine.