This paper describes an event dissemination algorithm that implements a topic-based publish/subscribe interaction abstraction in mobile ad-hoc networks (MANETs). Our algorithm is frugal in two senses. First, it reduces the total number of duplicates and parasite events received by the subscribers. Second, both the mobility of the publishers and the subscribers, as well as the validity periods of the events, are exploited to achieve a high level of dissemination reliability with a thrifty usage of the memory and bandwidth. Besides, our algorithm is inherently portable and does not assume any underlying routing protocol. We give simulation results of our algorithms in the two most popular mobility models: city section and random waypoint. We highlight interesting empirical lower bounds on the minimal validity period of any given event to ensure its reliable dissemination.