I recommend you don't use the conversions/reach number as your primary KPI. From my understanding, you spent $100 on ads, and got 300 conversions.
If a conversion isn't worth $0.33 to you, I would recommend re-examining your pricing structure and perhaps even model.
I may have misunderstood what you said, in which case I apologize. My point is not to criticize your effort, or deny your experience, but to correct a perspective I see a lot.
Don't worry about the number of impressions. Focus on how many customers you can get, then back out the numbers to find out how much revenue that made you.
But the success was because of the hype, not because of Facebook. We could have pulled this off on other platforms as well, we were 3 times in the news.
But the success isn't as big as it should have been. We paid pennies and had something. But I wouldn't want to know how much we should pay when I'm an actual business and trying to get some traction through Facebook
One thing I have learned in SEM and paid social -- it's difficult to extrapolate experience across projects.
I've had projects, appeared nearly identical, similar ad copy, targeting, etc. One was wildly successful, one was a flop. Going in, I remember assuming the second would be a big success, but it absolutely wasn't.
There is no should, there is only what happened. It's very difficult to project with sufficient accuracy, the variance swamps all.
If a conversion isn't worth $0.33 to you, I would recommend re-examining your pricing structure and perhaps even model.
I may have misunderstood what you said, in which case I apologize. My point is not to criticize your effort, or deny your experience, but to correct a perspective I see a lot.
Don't worry about the number of impressions. Focus on how many customers you can get, then back out the numbers to find out how much revenue that made you.