AI-generated Key Takeaways
- 
          Retention goal is a type of goal that helps advertisers optimize campaigns to win back lapsed customers. 
- 
          Other possible values for goal types include UNSPECIFIED and UNKNOWN. 
The possible value of goal types.
| Enums | |
|---|---|
| 
 | Not specified. | 
| 
 | Used for return value only. Represents value unknown in this version. | 
| 
 | Retention goal, which allows advertisers to optimize campaigns to win back lapsed customers. (https://support.google.com/google-ads/answer/14792043?hl=en) |