fathom - 2:01 pm on Apr 12, 2012 (gmt 0)
So anything done in moderation and varied is considered natural then? Outside of having links on spam sites?
Google clearly demonstrate that in it's paid links guidelines...
Google works hard to ensure that it fully discounts links intended to manipulate search engine results, such as excessive link exchanges and purchased links that pass PageRank. If you see a site that is buying or selling links that pass PageRank, let us know. We'll use your information to improve our algorithmic detection of such links.