The couple previously vowed to block the video's release, but TMZ reports that they have now reached a financial agreement with porn company Vivid Entertainment to allow the tape to be sold.
The deal is reportedly in the "six-figure range".
Vivid's president Steven Hirsch said that he is pleased the footage will be commercially available in the near future.
He explained: "We are excited to finally distribute this amazing DVD. Not only is it extremely kinky for a celeb sex tape, Karissa is absolutely beautiful. And as for Sam, let's just say he's no Smallville. This is sure to be one of our all-time best sellers."
Shannon gained increased notoriety earlier this summer after she confirmed that she recorded a sexual encounter with Hills star Heidi Montag.
