The announcement came as Trabzon's fans prepared to head for the club's stadium in the eastern Black Sea city for a ceremony to mark the 34-year-old's former Liverpool player's signing on a free transfer the day after a smiling Salah arrived in Istanbul in the team's burgundy and blue kit.
The club's statement to the Turkish stock exchange said Salah will receive a 20% share from products sold under his name, plus conditional bonuses each season.
The statement did not say how high the bonuses could go and what the bonuses are tied to.
Salah left Liverpool in the close season after nine years, having scored 257 goals in 442 appearances and having won the Premier League twice and the Champions League.
His output waned last season and he was left on the bench in Champions League games, leading to a public spat with Liverpool's then-manager Arne Slot.
Salah started his career in Europe at Swiss side Basel in 2012 and later joined Chelsea. He also had stints at Fiorentina and AS Roma between 2015 and 2017 before joining Liverpool.
Trabzonspor - generally considered to be the fourth-biggest team in Turkey after Istanbul sides Fenerbahce, Galatasaray, and Besiktas - finished third in the Super Lig last season to qualify for the Europa League playoff round.
The club's last domestic league championship was in the 2021-22 season.