Relationship, one-to-one, and permission marketing are just some of the new marketing lexicon terms used to describe online marketing strategies. It appeared to the authors that although these terms were much in evidence, little empirical work had been undertaken to measure the components of such strategies. This paper describes the results from a unique pan-European research study designed to understand the determinants of one of the elements in these strategies: a sticky website. It provides an explanation of the construction and parameterisation of a unique stickiness metric and explains why such a metric is important in helping eCommerce companies optimise their marketing mix. Fundamentally it demonstrates why purely behavioural measures are not enough and why attitudinal measures are important.