Profesional optimizers know that, nowadays it is crucial to post differentiated outer links - if they will be exactly the same, search engines will often ban the site or move it to lower positions during searches.
That is why the XRumer software includes a special variation system, that allows to randomly variate both the post's text and the links in it, therefore creating different posts every time without changing the meaning and readability of text.
Only buyers of the software can get any more details on this system.