Why go through the time-consuming hassle of queuing in supermarkets or shopping malls when nowadays a few clicks can get you pretty much anything, often at a lesser cost? More and more consumers have asked themselves just that – and opted for online shopping. But Web consumers can be very volatile. Online retail companies are constantly looking for innovative marketing techniques that will attract a new generation of frequent and faithful shoppers. Some, like the French site vente-privee.com, focus on giving their clients the impression that they belong to an exclusive shopping elite, with catchy video presentations advertising the luxury brands they sell at bargain prices. Others, like the retail giant Amazon.com, have mastered the use of cookies to tailor their website to individual Internet user's tastes. In some cases, though, online advertising has been viewed as intrusive, and web users are quick to reject overly aggressive marketing techniques. How far can companies go in getting to know their clients tastes and catching their attention, without invading their privacy?