The basics of backlinks and IP diversity is this.
Aim to get backlinks from websites with different IP addresses. Simple.
Getting several links from the same IP address is not SEO effective, they all count as one link
And you probably know this and are careful to only generate one link from a website to yours
It becomes a little tricky though when many websites in a wide variety of niches share the same IP address.
For example, Ning websites. There are, I am sure, thousands of Ning sites out their but there is no IP diversity with Ning sites. So getting backlinks from a hundred different Ning sites is ... Not SEO effective.
You are probably thinking 'What about article marketing?'
Any regular reader of this blog knows I am a huge fan of article marketing especially ezinearticles. 'But if I am submitting all my articles to ezinearticles does IP diversity not affect this?'
The thing about article marketing sites is you are hoping to syndicate those articles to other websites. The aim with ezinearticles is to have other webmasters take your articles including your biobox with your link and post these articles on their sites. That's where you get the IP diversity from with marketing through ezinearticles.
Obviously, if your articles suck so badly that no-one republishes them on their website, then yes, if you are using just one article directory then your hundred backlinks from a hundred articles has the power of exactly ..one
So take the time to check the IP addresses of the sites you are getting your backlinks from especially if you are using a footprint to build links.
To check the IP of a site, just do a Google search for 'check website IP' and a lot of options pop up
Also you can assess the backlinks that your website already has to ensure that there is link diversity in two clicks
Use SEO elite to analyze the backlinks to your website. SEO elite gives the IP addresses of all the sites it finds that are linking back to the webpage you specified. It's quite easy to see therefore if your backlinks are all valid and from different IPs or not