Recommendation widget, articles
| Metric | Name | Description | Type | Filtering option | Minimum date for report generation | 
| 
 | Article impressions | An impression is when an article in the widget is shown to the page user. An article impression is counted if at least 50% of the cell was in the user's viewport for at least 2 seconds. Built on the  | 
 | present | 2020-03-01 | 
| 
 | Clicks on recommendations | Number of clicks on recommended articles. Built on the  | 
 | present | 2020-03-01 | 
| 
 | Article viewability rate | The ratio of the number of article impressions to renderings. Built on the  | 
 | present | 2020-03-01 | 
| 
 | Article CTR | The ratio of the number of clicks on an article to the number of impressions. Built on the  | 
 | present | 2020-03-01 |