Introduction Within an informing system, resonance refers to the ability of a communication to make its way from sender to client once it has already met the standards of quality (e.g., rigor) and usefulness (e.g., relevance). When the term was introduced (Gill & Bhattacherjee, 2007), it was further proposed that resonance had two distinct aspects. The first was the ability of the message to inform a single client. The second was the ability of the message to produce subsequent client-to-client informing activities. Because the theory behind achieving single client resonance is addressed elsewhere (Gill, 2008), the present paper will focus strictly on achieving resonance between clients within the client-to-client component of an informing system. This can be a particularly important process within systems that involve the transfer of complex information. The diffusion of innovation literature (e.g., Rogers, 2003) finds, for example, that client-to-client processes dominate all but the earliest stages of knowledge transfer. Moreover, several different models, mathematical and empirical in origin, have been proposed for a variety of information tasks, but relatively few have been employed within the informing sciences. Thus, the overriding objective of the present paper is to introduce some of these models and consider their respective domains of applicability. We begin by assuming that a message--of acceptable rigor and relevance--has been transmitted by a sender to a very small number of clients within a client community who have subsequently absorbed the message into their own mental models. Our interest is then to understand what subsequently happens to that message within that client community. In the present paper, we consider three models that make fundamentally different assumptions about the nature and motivation for communications: 1. Criticality models: This model is based on the concept of a critical system, most commonly used in the context of nuclear engineering. The simplest of the three models, it could be described as client-sender motivated communications, since it is applicable only when one client who possesses the information is strongly motivated to inform other clients about it. 2. Information Cascade models: Introduced originally in economic theory, this model is normally presented in terms of a client's making a choice between two options for which information about prior client adoptions is available. Although often applied to products (e.g., VCR formats, movies), it can also been applied to pure informing situations, such as the enrollment decision made between alternative classes or the choice of a research topic. It can be characterized as client-recipient motivated informing, since it is the potential recipient who actively decides which option to pursue. 3. Tipping Point models: Building upon assumptions presented in Gladwell's (2000) widely read book The Tipping Point, this model is typical of general diffusion models (e.g., Rogers, 2003) that examine how innovations--including ideas--migrate through communities. It could be characterized as a social-task model, since informing is motivated by both task performance-related criteria and by social criteria. As each of the three models is presented, relevant literature is reviewed. For each model, key parameters that impact informing are identified and a simulation based upon the basic concepts of the particular model is developed. Interesting areas of behavior highlighted by the simulation are then presented and discussed. Finally, areas where each simulation could benefit from refinement are noted. At the end of the paper, some general conclusions regarding the application of the models are presented. Central to these conclusions is the assertion that the client-to-client informing phenomenon is very important. …