I’ll paraphrase google here: Rather than trying to fix something just for the sake of trying to manipulate google, Try to make better content and to make it better in other SEO ways.

Fix pretty urls.
Fix keywords and use the <h1>, <h2> and <h3> tags.
Make your content unique, not just taken directly from a feed or copy-paste it.
Don’t make collages for your images, set up each one as an individual image (google images can give you an insane amount of traffic if you just set it up right)
Don’t link to bad neighborhoods
Post often enough, and try to spread it out so that it’s an even stream not in bulks every now and then

For google to look upon them as separate sites they only need to be on different subdomains (blog.example.com is considered a different site than example.com) For example there’s a lot of blogs on blogspot.com, in google’s eyes most of them are separate individual blogs because they’re all on a different subdomain. example.com/blog would not be different from example.com for example

If you really feel you need to go down the road of putting them on different ips (there’s no need to put them on different servers as long as you fill the coming criteria), you need to get them far away enough in the IP-address block space so that any human or machine can’t guess they’re the same. Putting one blog on 10.11.12.1 and another on 10.11.12.2 is not far enough away (according to those that dwell upon this issue, I do not feel I’m in that group ). You need to have them on different C blocks.

Hope this helped.

thanks guys! that clears it up for me then. yes, they’re all run on the same VPS server (shared) but all have unique domains and all have unique custom content. in which case, after reading your two comments, there’s no reason why i should do things any differently or change the setup. that’s good to know. thanks!

I’m using one domain with several sub domains on one shared server. They’re doing okay with Google. They are new and I made a mess of importing some from blogger (the tags became categories, so there’s far too many of them!) but Google is sending me traffic. It’s definitely true that they are seen as separate domains and each is valued differently regardless of the hosting or the primary domain.

I’ve never heard that cross linking suggestion before. But I did do this in the beginning automatically. However, I’ve now moved from this and link the less popular blogs to the most without a recip.

My theory at the start was that I wanted to keep the traffic on my own blogs until they left to a sponsor. So they might arrive for one thing, but then see all the other blogs listed and stay in the circle, hopefully until they decide to buy.