This book examines what happens when consumption – originally based on ethical issues – becomes a sort of religious behaviour which excludes possibly equally-valid alternatives by principle. It happens when consumers are deeply observant of the choices they made that it becomes a sort of faith, a recurrent behaviour which excludes a renewal of critical judgments and usually turns into habit or, even, fanaticism. Five related studies are presented in both consumer and political marketing: from fervid attachment to brands, to induction of compulsive forms of shopping or, even, fanatic behaviours, such as political extremism. On these themes, this volume offers a European point of view and, in particular, an Italian one, proposing new and original lines of research that have never been explored before.