In this model, the magazine is sold to readers for a price, either on a per-issue basis or by subscription, where an annual fee or monthly price is paid and issues are sent by post to readers. Paid circulation allows for defined readership statistics.This means that there is no cover price and issues are given away, for example in street dispensers, airline, or included with other products or publications. Because this model involves giving issues away to unspecific populations, the statistics only entail the number of issues distributed, and not who reads them.