The persuasive abilities of advertising and therefore, advertising effectiveness, have been discussed extensively in advertising literature. In particular, the components that make an advertisement effective have intrigued both advertisers and advertising agencies over the past three decades. Likeability of advertising is suggested to be a key indicator of advertising effectiveness (Haley & Baldinger, 1991) yet, the literature in this area concentrates on establishing what likeability is rather than exploring the effect of likeability on consumers' behaviour. Given the level of interest that has been driven by claims that likeability can heighten the persuasiveness of an advertisement, it seems pertinent to investigate the effect of likeability on consumer behaviour. The research reported in this thesis examined the effect of more and less likeable images on consumers' choice behaviour. The data for this research was obtained from a cross-sectional survey in which choice modelling techniques were used to establish consumers' choice behaviour. This data was used to investigate the effects of likeable images on consumers' choice behaviour for the product category of milk. Overall, it was found that advertisement likeability had a very weak effect on consumers' choice behaviour. Furthermore, it was established that the type of milk variant was the most influential attribute in determining consumers' choice behaviour. Price was also an important factor although this attribute was far less influential than the type of milk attribute. However, the research found some support for the idea that likeability enhances the salience of advertising, as likeability did improve the salience of the advertisements for different groups of consumers within the sample. The main implication that arises from this study is that likeable advertisements do not necessarily lead to consumers changing their purchasing behaviour. Likeability is one of many measures of effective advertising and does not appear to command more attention than any other measure of effective advertising.