Reddit has placed a ban on a few high profile sites, including BusinessWeek, The Atlantic, Phys.org, Global Post, and Science Daily. They claim that these sites have been “artificially promoting their content [on Reddit] to make it appear more popular.”
Reddit deems this an offense that undermines the integrity of their site. They are an open-source forum with content curated from their users. If these sites are allowed to aggressively post self-promotions, then Reddit feels they will become nothing more than an advertising platform.
One user was also banned from posting to the site on the grounds that he was promoting content from the banned sites.
It will be interesting to see how Reddit proceeds with this strict action against these sites. Their popularity is dependent on the free nature of their site. If they want to prevent sites from promoting themselves, they will need to draw lines as to what users can and cannot do.