Assigned reading Purves et al., pp. 185-215, Plant Ecology, M. J. Crawley, ed. A way to exchange genes and maintain variation. Movement of genes within populations, and occasionaly between, most pollen doesn't go very far from the parent plants. BUT sometimes not as important as assumed.
Many mistakes occur.
In many habitats, a large number of flowers may compete for a limited number of pollinators. In other habitats, the opposite extreme may exist. Timing of floral presentation often is linked to pollinator availability. Character displacement may occur in either the flowers or the pollinators. How many actually ovules actually do get fertilized depends on the system.