[annamargot]

This is the correct answer.

Ask yourself why Facebook counts "post-view" conversions instead of only post-click like AdWords and most others.

New client had been working off the assumption they were seeing ROAS of around 3 (not terrible). When we showed them how to see just the post-click, ROAS is now at 1. That means even if they are selling a product they received for free or stole, ie COGS = 0, they still only breakeven.

Attribution is the key. All this assumes that ad companies and Facebook are honest in the first place about the number of views and clicks an ad has received. Their behavior does not engender much good will for a benefit of the doubt situation.