Most seeds of most plant species are dispersed over distances shorter than a few dozen metres, and only very few seeds travel over long distances. While the long-distance dispersal (LDD) of seeds is, thus, typically rare, it has disproportionately large effects on the long-term and large-scale dynamics of plants. Here, we first highlight the importance of LDD for various aspects of plant biology, discuss problems with quantifying LDD, and advocate a new vector-based framework for LDD research that may help to overcome some of these problems. We then present six generalizations about LDD mechanisms that can be derived using this framework. While the framework and the generalizations are also highlighted in Nathan, R., Schurr, F.M., Spiegel, O., et al. (2008) Mechanisms of long-distance seed dispersal. Trends in Ecology and Evolution 23, 638–647, this chapter provides a more in-depth derivation of the framework and additional evidence for the generalizations. In particular, we present here a new meta-analysis validating an innovative model for the allometry of seed dispersal by animals. In the second part of the chapter, we extend Nathan et al.'s (2008) discussion of the implications of the framework and generalizations for understanding LDD evolution and forecasting large-scale dynamics of plants. In particular, we use the vector-based framework to address two fundamental questions about LDD: can we identify all relevant LDD vectors and can plant traits influence LDD? We conclude by suggesting directions for future research on LDD.