The possible sub types of customer lifecycle optimization goal.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v26/enums/customer_lifecycle_optimization_goal_sub_type.proto)

| Enums ||
|---|---|
| ## `CUSTOMER_RETENTION_ONLY` | Customer retention only. |
| ## `CUSTOMER_RETENTION_VALUE` | Customer retention value. |
| ## `LOYALTY_RETENTION_BENEFITS` | Loyalty retention benefits. |
| ## `LOYALTY_RETENTION_VALUE` | Loyalty retention value. |
| ## `NEW_CUSTOMER_ACQUISITION_ONLY` | New customer acquisition only. |
| ## `NEW_CUSTOMER_ACQUISITION_VALUE` | New customer acquisition value. |
| ## `UNKNOWN` | Used for return value only. Represents value unknown in this version. |
| ## `UNSPECIFIED` | Not specified. |