Parameters for an experiment to create a Performance Max campaign. The experimental Performance Max campaign gets created automatically based on the existing SHOPPING campaign settings and the settings specified in this field.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v25/resources/experiment_arm.proto)

| Fields ||
|---|---|
| ## `bidding_strategy_type` | `https://developers.google.com/google-ads/api/reference/rpc/v25/BiddingStrategyTypeEnum.BiddingStrategyType` Immutable. Bidding strategy type of the Performance Max experiment campaign. |
| ## `budget_amount_micros` | `int64` Immutable. The amount of budget of the Performance Max experiment campaign. |
| ## `target_cpa_micros` | `int64` Immutable. Target CPA of the Performance Max experiment campaign. |
| ## `target_roas` | `double` Immutable. Target ROAS of the Performance Max experiment campaign. |