  Due to the recent popularity of online social networks, coupled with people's
propensity to disclose personal information in an effort to achieve certain
gratifications, the problem of navigating the tradeoff between privacy and
utility attracted a lot of recent interest and generated a rich body of
research. A critical prerequisite to solving the problem is to appropriately
capture the privacy and the utility aspects in the problem formulation. Most of
the existing works' focus is on the notion of privacy, while utility loss is
often treated as the undesirable but necessary distortion of the true data,
introduced by the privacy mechanism. By contrast, we are interested in
modelling utility differently, by associating it with specific attributes of a
user, just like privacy is associated with specific private attributes in the
literature. Our model of utility facilitates a better and more precise privacy
mechanism, and achieves better privacy-utility tradeoffs. We further
incorporate into our problem formulation a practical constraint on acceptable
loss in utility per unit gain in privacy, which allows users to customize the
privacy mechanisms in order to account for the relative values that each user
associates with their own privacy and utility. This paper discusses the
intricacies of our utility model and the corresponding privacy-utility
tradeoff, and introduces a heuristic greedy algorithm to solve the problem.
