Why do creators stop promoting after the first month?

Hi everyone, one question:

I’ve noticed a common pattern with affiliate and creator programs:

Creators are active in the first few weeks, then engagement slowly drops.
Less promotion, fewer mentions, and eventually… silence.

I’m trying to understand what usually causes this.

Is it:
• Low commissions?
• Payout delays?
• Lack of visibility into performance?
• Or simply not enough incentive to keep promoting?

For successful store owners who’ve built long-lasting affiliate or creator programs:
What actually keeps creators engaged over time?

I’d really appreciate hearing practical advice based on real experience.