For which of these sales promotion tools is the evaluation of success or failure the most difficult?

Name: For which of these sales promotion tools is the evaluation of success or failure the most difficult?
Brand: Quizplus
Rating: 4.9 (66 reviews)

Question

Quizplus · Accepted Answer

Calendars, as a sales promotion tool, are more challenging to evaluate in terms of direct success or failure because their impact on sales or brand loyalty is less immediate and harder to measure compared to more direct and quantifiable tools like coupons, rebates, and referral gifts.

For Which of These Sales Promotion Tools Is the Evaluation