Penny vouchers, which allow consumers to pay 1p for a newspaper, are likely to be classed as bulk sales under changes to circulation rules.
The Audit Bureau of Circulations (ABC) is thought to be considering changing the rules at its next council meeting. The proposed changes would mean penny vouchers were no longer classed as full-rate sales.
Penny vouchers have been used by the Scotsman as a marketing device. It ran a direct mail campaign, distributing vouchers that were redeemable against the price of a newspaper if customers paid a penny.
The vouchers helped the Scotsman increase its average circulation for the six months to December to 100,441, up 32.58 per cent year on year.
However, other media owners consider the promotion contrary to the spirit of the rules, which lay down that where newspapers are distributed free on trains, planes and in hotels to readers, they are classified as bulk sales.
Newsagents have also become disgruntled because, after accepting a voucher and a penny for the newspaper, they have to wait to be reimbursed by their local distributors.