If you are one the line about purchasing this sourcebook, then I'd like to think that this review will sway you to the correct choice. Ghouls: Fatal Addiction is a Vamprie sourcebook explaining the physiology, psycology and systems of mortals with Vampiric powers. It is an amaxing supplement, but I should warn people that it is extremely twisted, and meant for mature readers.
Ghouls are slaves to blood. They are addicted to the vitae of Kindred, drinking of it three times to gain a new discipline in potence. Many of them just live for their next fix of the power juice. While still mortal, they gain many of the traits of Kindred. They can frenzy, though it is more difficult, can learn disciplines and expend blood to make themselves more physically powerful. The Ghoul is a wretched creature, more powerful than a human but bound to Kindred for their new substance.
The supplement provides quite a bit of information on how different Ghouls see Kindred, and how the Kindred see them. The book provides information on how each clan treats their ghouls and how a faction of Independant Ghouls sees the different sects and lineage of the different Vampires. In addition to this, we see how different age groups among Kindred see their ghouls.
The sourcebook provides rules for three different kinds of Ghouls, Vassals, Independants and Revenants. Vassals are bound to a certain Kindred, doing any needed work to get that special substance. Independants have no master. While this means freedom, it also means that they have no steady supply of vitae, and are forced to get it somehow to survive. Revenants are entire families of Ghouls, usually within the Sabbat. This twisted and inbred creatures produce vitae in their own body and live three times longer than a normal human. Ghouls: Fatal Addiction also includes ideas for running chronicles with Ghouls as the characters. This means that you could have a Ghoul in a coterie of Kindred, or an entire group of Ghouls.
This is a great sourcebook which should be read by any Vampire: the Masquerade storyteller. Just ignore the art and you'll love the book.