paid and not paid Backlinks

[Castleonthehill]

The higher the page's PR and the fewer links on it, the more link juice a link from the page can pass to your site. From an SEO perspective backlinks are like votes for your site, so "paid" backlinks aren't trustworthy. But I know a lot of companies that do pay for backlinks and I don't believe Google will penalize you for it - Its a gray hat tactic. Gray hat tactic are considering to be risky but not rule breaking.