But as I said the more 'relevant' the site on which your backlink appears the more powerful the Backlink will be. In fact, a backlink from a site perceived by Google as unsavoury or spammy can actually hurt your rankings.
Another thing to remember is that backlinks are how the Web is mapped. The little 'bots' that travel around, and index, the web can only 'travel' via links they find as they 'read' your websites and others.
In the past just sending 1000's of backlinks from anywhere to your site was the norm, and it worked - until Google changed the rules by which they rank sites ( i,e, their 'Algorithm'). This is something they do regularly which is why your Backlinks should be squeaky clean and why, as mentioned in the videos below: a few 'quality. backlinks are better than a hundred weak ones.>