Everybody knows that there is no better and more effective promotional means that by adding a well-written article on a thematic website or, which happens more frequently, blog. Smart SEO experts already own their networks of thematic blogs and keep them in good SEO shape, mixing posts with links with posts with no links. Typically, you would charge a post with link(s) one-time and place it permanently. But "permanently" in most cases is a matter of a year, few years (or even one month if you deal with some Indian SEOs ) ). Do you think it is justifiable to charge the client on a yearly basis for a blogpost link?