A lot depends on how well you can model attribution. If you&#x27;re measuring last-click, you&#x27;re going to see a wildly different story than if you can measure the impact the measure of a impression, mid-stream click, etc. I&#x27;d guess most small businesses are not invested in developing stronger attribution models, so looking at Facebook spending vs. something like paid search, as apples-to-apples, is going to make Facebook look worse than it likely is. That&#x27;s not to say advertisers aren&#x27;t chasing metrics other than ROI, but just calculating an accurate ROI can be something beyond the scope of many.