This paper provides the first empirically based marketing model of the perceptions of givers and the resulting impact on donations. Within nonprofit marketing there is a considerable amount of extant research to support the view that both extrinsic and intrinsic variables can be used to separate givers and non-givers to nonprofits. However, they are less useful in explaining the level of support that will be offered. Perceptual factors may offer more utility in this regard. Structural equations models are presented based on a survey of over 1300 donors that link a series of perceptual determinants to the level of the average donation to a specific organization. The potential mediating roles of trust and commitment are also explored. Trust appears unrelated to the direct benefits that accrue to donors as a consequence of their gift. Rather, trust (and indirectly, commitment) is predicated on the perceived benefits supplied to beneficiaries and the manner in which the impact of these benefits is communicated back to donors.