I've been doing some research on some niches. But when I check the number of backlinks every website ranking somewhere on the first page has I find out there is a HUGE difference between the number of root domains linking and the total number of links (I'm using OSE). For example, this one site ranking first for a certain keyword has 150 root domains linking to it but the total number of backlinks is 5000. That's an average of more than 30 backlinks per root domain. If I would be to start competing for this keyword, would I need a couple of hundred backlinks (from unique root domains) or should I aim for thousands? Does Google value multiple backlinks from one domain really that much? I know there are a lot more factors to consider, but I'm just looking for a rough ballpark figure. My second question is about PBNs. How many outbound links to my money site can a domain in my PBN have? Everywhere I read people are saying 1 to 3 outbound links per domain to your money site tops. But when I'm looking at some websites with top rankings that are obviously using a PBN, I find some of their domains having multiple outbound links to their money site on each page (sometimes adding up to hundreds of links from one domain) without any other sort of outbound links. Yet they are still ranking top 3, so what does that mean? Do they rank higher because of this practice? Shouldn't they get a hit from Penguin? This isn't just an isolated case or something, I've found dozens of websites like this.