Consumers find it difficult to evaluate services they have not previously used, especially where these services have high experience or credence properties (Mittal 2002, 2004). A frequent promotional strategy used by marketers is to offer a free trial, such as a free brake check on cars or a free session at a new gym. While there is extensive literature on product trials, very little research has been conducted on free service trial offers. This led the researchers to undertake preliminary content analysis and qualitative interviews and ultimately to develop a comprehensive model of consumer evaluations of these offers. The model takes account of the type of service on offer, the manner in which it is offered and the pricing mechanism used (free versus discounted). It also characterizes the cognitive and emotional evaluations consumers make in response to these offers and how these contribute to trial and purchase propensity. Individual characteristics of consumers, such as deal proneness, were also incorporated into the model. The current study reports an experiment where the model was systematically tested among groups of male and female consumers (in total 400) who varied by age group and service experience. The research indicated that a free trial offer operated rather differently from a discount, inducing a sense of obligation which motivated some people to adopt the trial and subsequent full service offer. Traditional trial-cognition-evaluation models (e.g. Smith and Swinyard, 1983) are not sufficient to explain the phenomena uncovered by this research.