Overspending can happen because ad traffic and billing are not always instant.
Your campaign may still receive clicks or impressions that were initiated before the pause or limit was reached. These interactions are processed afterward, and their cost is charged to your account.
Other reasons may include:
• Traffic already in transit from publishers
• Delayed billing or postback processing
• Auction cycles completing after limits are hit
• System buffers to ensure stable delivery
Overspending is typically small and limited.