There's some discussion that new links from the same site count a bit less with each increasing link.

Personally, I haven't been able to prove that common wisdom.

That being said, I wouldn't want to go back to doing SEO as you're describing, increasing I don't think sitting a single foot outside of the guidelines is a good long term approach-

Can anyone describe backlinks in details?

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Back links come from various visitors to your site. The higher ranked visitors the better. There is no way you are going to trick Google. It is a natural process and will take time. The more you give, the more you get. It is all about reciprocity. Just my two cents!

try to get links from different domains, single domain will increase number of refering pages only.

I think it is not a good idea at all so that try to make back-link is another website/forum/blog.

Use social bookmarking for your site then you can get easily backlinks for your website.

For the keyword you are targeting you need to know the competition and traffic for that keyword, google keyword tool is the best for keyword research. For getting blog post on first page, the keyword you are targeting plays an important role. Try to choose a keyword that have massive traffic and less competition. Backlink from same website does not help that much.

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