Active subscriber
Active subscribers are all the subscribers in your Laposta list(s) to whom you can send a newsletter directly.
Subscribers who have unsubscribed or who were cleaned from your database do not count when determining the number of active subscribers. If the same email address appears in three different lists, this subscriber is counted three times as an active subscriber. After all, all lists in your account are separate from each other; no (subscriber) data is shared between them.
Unique subscribers
Unique subscribers are all of the email addresses you have added to your account. Not just currently, but over the duration of your (free) account. If the same email address appears in three different lists, this subscriber is counted once as a unique subscriber.
Your account
Because the number of active subscribers fluctuates as a result of subscriptions and unsubscribes, the average number of active subscribers is used to determine your tariff group.
The average number of active subscribers per month, and the annual average based upon this, is kept for you in Laposta.