If you read the description, they don't charge for links. If you register a link, they guarantee that the content stays at that linked site for some time. Most sites have lots of dead links. If you don't want the link to go dead you can pay to guarantee that. If you don't care, just link to them and take your chances. Companies don't like dead links on their websites (especially to articles that say nice things about them) so they are willing to pay to make sure the article stays in place.
Simply put - you can link to whatever URL you want. It is just a question of whether there is something at the other end.
Slashdot Mirror
If you read the description, they don't charge for links. If you register a link, they guarantee that the content stays at that linked site for some time. Most sites have lots of dead links. If you don't want the link to go dead you can pay to guarantee that. If you don't care, just link to them and take your chances. Companies don't like dead links on their websites (especially to articles that say nice things about them) so they are willing to pay to make sure the article stays in place. Simply put - you can link to whatever URL you want. It is just a question of whether there is something at the other end.