I doubt Google would do that. It's actually difficult to distinguish what's relevant and not until you get to see the page. What if a gardening blog discusses about the best vehicles used for transporting delicate plants and places links to a car's website?
i think that if u have relevant back links that it will help to get ranking for that anchor text as well as pass the pr.where as if u have inner link from not relevant sites than it will help in indexing your site and pr will pass but it wont help in SERP.
Whether the link is Relevant has nothing to do with page rank. Non-relevant sites pass exactly the same pr as a relevant site. Links from sites that are not relevant can help. However it is best practice to get links from relevant sites.
Yes that's true my friend. You must get many backlinks with relevant to your site. 'Coz getting backlinks from unrelated sites is link farming...It will give you high PR but it will not rank in any SE.
So do links from non-relevant sites pass on NO help with the SERPs or do they pass on only nominal help? I would be more inclined to think the latter but I've seen people state both.
Personally, I don't try to get links from un-related websites. If they come on their own, well thats fine but I wouldn't pay or exchange for them unless you thought you were going to get enough traffic from it to justify the cost in sales. I don't play it like a numbers game, I have some sites outranking other sites with 10-20X my links.
It is true. A back link is always there but one from your niche is better then one from a none related niche.