Possible YouTube ad benchmarks sources.

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

| Enums ||
|---|---|
| ## `CATEGORY` | A Product \& Service Category. |
| ## `INDUSTRY_VERTICAL` | The classification of ad categories for benchmarking. (for example, "Technology" or "Finance"). |
| ## `UNKNOWN` | The value is unknown in this version. |
| ## `UNSPECIFIED` | Not specified. |