People are always talking about the link relevance if it comes to backlinks. If you have a niche site, would it be better to collect backlinks from theme related sites only and reject backlinks from not theme related sites even if they are backlinks with medium or high PR? Does this really make sense?
Yes, it is better to collect backlinks from theme related sites but every link is important so I think you should not reject links from non-related sites - at least I do not do it. Anyway - If you run a site with interesting and catchy content you will very often get theme non-related links so I see no problem.
Whatever you do - do NOT reject backlinks from not theme related sites. Each and every link helps a bit. But when buying links focus on links from related sites
I think it is more down to theme related pages rather than sites. A general site might have a highly relevant page and this is pretty much as good as the same page on a related site. To judge how related a page is I look to try and get my keyword in the page title, URL and H1. This is why article submission is one of my favourite link development techniques.
So I understand it that way that a site dont get penalized for being linked from non-related sites? That would be just fair because you cannot choose whoever is linking to you.
That is right. You got the point. A links is a link. The non-relevant links is not that good as the relevant but is still good
As noted - the relevance of the page or the post is of more importance than the overall relevance of the site. On topic, contextual links are generally the best - but I wouldn't necessarily reject links unless they are from sites that you don't want to be associated with.
External factors that don't depend on you can't penalize your site. Otherwise is would be too easy to sabotage your competitors
I agree with what has been said thus far all links are valuable whether they are relevant or not because you may get some traffic and it will improve your rankings in the serps.
every link helps regardless of relevance but I think relevant back links help with your ranking on google search engines
Every link counts - I would only reject porn, gambling or other potentially damaging links. Topic specific links, especially when the link is surrounded by relevant text are best - you get a lot of credit for those links. Which is exactly why spammers insert related text (not linked) around their links when they spam your blogs.
Well you can't control everything because sometimes people would want to link naturally to your site if it has quality contents but when it comes to your own link building effort, then you can choose and select.
Now days webmasters creating sites for only link exchange purpose that is only link farm so try to avoid those sites
Ok now I am confused. In another posting I have just found this: h ttp://forums.digitalpoint.com/showpost.php?p=8960670&postcount=67 That thread is very interesting. However that makes me ask: What is relevancy for Google? How is a page linking to my page determined as relevant? Pages that appear on SERPs before my page obviously must be relevant related to the search query. Does that mean I should try to get backlinks from these pages listed? Or is PR connected to the keywords in any way like this quote suggests: Or is he talking about SERP-ranking here?
relevancy is common sense, if it's not close to being in the same niche, and if it's a niche specific site, then you will know very quickly whether or not it's relevant. E.g. plumber site would NOT link to pharmacy site = OBVIOUS paid link
Even more important, I would say, than page relevance is contextual relevance. That is, G recognizes the ~20 words or so (about a sentence) surrounding the link as being the relevant text that corresponds to that URL. Take the links in this thread, for example. The actual pages that provide backlinks for the target site have no actual topic, but rather multiple topics in multiple sentences/paragraphs - hence making them a relevant, authoritative link.