Possible optimization mode of a customer acquisition goal.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v23/enums/customer_acquisition_optimization_mode.proto)

| Enums ||
|---|---|
| ## `BID_HIGHER_FOR_NEW_CUSTOMER` | The mode is used when campaign is bidding higher for new customers than existing customer. |
| ## `TARGET_ALL_EQUALLY` | The mode is used when campaign is optimizing equally for existing and new customers, which is the default value. |
| ## `TARGET_NEW_CUSTOMER` | The mode is used when campaign is only optimizing for new customers. |
| ## `UNKNOWN` | Used for return value only. Represents value unknown in this version. |
| ## `UNSPECIFIED` | Not specified. |