Many visitors to trade fairs register in advance via the trade fair website. Their voucher are then printed at home or in the office. On arrival at the trade fair they all get a entry badge. An advert on the voucher offers an effective way of promoting a special trade fair offer (trade fair deal). Unbeatable in combination with the trade fair deal on the website.
This can also be posted free of charge on the trade fair website. Price per voucher.