In Great Britain, Ireland and the US, during the 17th to 20th centuries, public houses sometimes issued tokens which could be used in payment for future drinks.
As the token cost less to produce than the value of the drink, there was a significant profit to the bar owner.
This has been cited as the reason bar owners loved tokens, and they were found in virtually every drinking establishment.
The early tokens were usually made of brass or aluminum and would have the name or initials of the pub on them, so that they could not be used anywhere else.
This ensured that, when the pub changed hands, the new landlord would not have to honor old tokens.