Desensitization.
Customers become desensitized the more times they see a particular type of offer / experience. It no longer holds as much value for them, because it becomes commonplace.
- Inflated compared at pricing: "Was $199, now $49."
- False scarcity signals: "17 people viewing"
- Overly obvious influencer promotions / sponsored posts.
- Reviews without pictures or video.
- "Free shipping."
These things either become expected, or become noise to ignore. Why? Because the consumer has seen it so many times before. It's no longer special.
This is why certain strategies work for a time, then fail.
It is with this understanding that one can create an offer, a user experience, and a brand which genuinely converts.