If I have dozens of websites in different IPs and all the domains registered in the name of one single company(ownership), some websites links each other, will these kinds of links count for SEO?
You are right, I use unique content in each website. Do you think google check the domain register ? Because I found google.com's top results only from US domain register in my field !
Google does establish a relationship between websites with domains registered to the same entity/person. And also that are hosted in the same C block / that are probably on the same server. It's not 100%, but does add to their formula.
Google's search algorithm is not a simple one-liner based on page-rank alone, and its not based on one thing or another, there are hundreds of co-factors. Google has many people working for them and not all of them work in automation! Some do manually check the SERPs, Some do manually check for spam in their indexes So does Google do one thing or another.. No, they do many things to check for black-hat techniques! if you see something as black hat / slightly dark, you can sure as hell bet your ass Google will too... soon enough. If you link to your self from thousands of sites all registered under the same domain, its just not worth it in the long run In fact, as page rank is becoming so corrupt, I think page rank will be phased out in favour of plus-one, but that's just a gut feeling
I use unique content in each website. Do you think google check the domain register ? Because I found google.com's top results only from US domain register in my field!