Facebook Ads: Reach vs. Impressions. Which do you use in your campaign reports/calculations and why?
I agree with other answers that the cost per action is the final most important number, but in reporting to clients I use both impressions and reach.
Specifically for launch campaigns, I like to share with clients details of how many people we were able to reach and how often they saw an ad.
I use both metrics in planning with a client to get the most for their adspend dollars.
Often launches are more about reaching the people who already know the client vs finding new leads and growing a list (that is before the launch).
Based on audience sizes I can make educated calculation on how much budget we will need to apply to reach as much of that audience as possible.
I think sharing this with the client, helps them understand that i am being judicious with their money and it’s not just a guess.
Some clients come in with a specific budget. In this case I can give them an estimate of how many people we can show ads to.
Some clients come in and want to reach as many people as possible in a particular audience. So I use the estimates from Facebook and industry averages to come up with a proposed budget.