Generally speaking, Billable views (Ad, Video) and regular views (Ad, Video) are identical. The main difference in these metrics is found in one of the cases when revenue events are not associated with ad or video view events.
An example of such event on the AOL On Network is when content outside AOL On is accidentally distributed to AOL On publishers, the views are not counted as billable. Furthermore, if a video play event doesn't have a vvuid (Video View ID), it is not billable because without a vvuid we don't know how to link it to a monetization event.
Billable views are the source of truth for our end of month revenue numbers, so in general for revenue reporting, we recommend using these metrics.