Techniques are described for facilitating the awarding of prizes in chance-based contests in various ways, such as chance-based contests which are part of promotional advertising, etc. In at least some embodiments, the techniques include facilitating the awarding of prizes at the time a contestant enter or plays the contests, while awarding a selected number of prizes, which may be determined before the contest starts. In at least some embodiments, the techniques include employing an award counter to control awarding of prizes in a chance-based contest. For example, an award counter may be incremented at random or pseudo-random times. In at least some embodiments, the contest is associated with a location-based virtual group of users that has one or more associated geographical areas.