When you run your detectors, or perform advanced detector training you are charged credits based on how much data you process.

Running Detectors:
You are charged 1 Credit per 1 Megapixel (1 million pixels) your detector processes.

Training Detectors:
Your first 500 training steps per detector are free if you are on a Professional and Enterprise plan. For most use cases 500 training steps should be sufficient. If you wish to train more than what is included in your plan you will be charged 2 credits per additional 100 training steps.

Additional Credits
If the credits included in your subscription plan are not enough you can purchase additional credits at any time.