Paid links are a source of great controversy. Google says buying links is bad, but some savvy webmasters can work around the confines while still staying white hat regarding these tricky shades of gray.
WHY are paid links considered taboo? It all has to do with trust. An inbound link is a thumbs up that our site is valuable. We all want to gain a spot on the first page of the SERPs. If other sites give us back-links because we have impressed them, these are honest recommendations.
However, when black-hatters pay for links from other sources just to increase rankings Google starts to frown. Companies which sell large amounts of links and advertise that they will substantially increase your Page Rank need to be looked at closely – the sites linked to you through such programs are usually totally irrelevant and can raise red flags.
Your site probably doesn’t want links from casinos and insurance sites; these send up a warning to the search engines to spiders that you are trying to increase your PageRank by getting incoming links, but not in the spirit of righteous linking.
You CAN trade links, but reciprocal links are often also not considered natural links … although, keep in mind – if you are building links mainly for traffic to your site, then reciprocal links, links bought from websites relevant to your own and text links can be extremely beneficial.
You must make sure to no-follow these types of links so Google doesn’t think you are gaming the system. They can penalize heavily if they think you are trying to cheat!
Now, you can pay someone to create links for you from forums and blogs, just make sure they do so with respect. You don’t want to get in trouble for spamming!
Watch yourself and tread lightly. When in doubt, no-follow. That’s teh best way to avoid teh dangers of paid links!