Do honest timers convert better?

As an e-commerce manager, I'm skeptical about countdown timers. Are they genuinely effective conversion tools, or just another gimmicky marketing tactic? I want to understand if customers perceive these timers as manipulative or if they actually create meaningful urgency that drives purchases. My team has debated implementing dynamic timers, but we need concrete evidence about their psychological impact and real conversion potential across different product categories and customer segments.