In many marketplaces consumers may interact with more than one supplier in order to achieve a particular goal. This paper takes the position that trust mediates agent interactions and that agent demands are likely to increase with increasing trust. Furthermore, trust of one agent in another is updated based upon a trust model. The model proposed in this paper is one in which agent demands can be divided amongst suppliers with the division determined by trust. The model evaluates five prominent trust models in a hypothetical marketplace and demonstrates empirically that FIRE, Regret, Probabilistic Trust Models and a model due to Yu and Singh can be exploited such that a consumer agent will continue to interact with a malicious agent despite periodic contract defaults by the malicious agent. Empirical studies support the hypothesis that adaptive trust models such as AER are resistant to this type of exploitation and discourage periodic or cyclical defaulting on contractual obligations.