So I promoted this post to see the impact.
I got twice as many views. Of course, as a user (not a page’s promoted post or the boost post), I don’t know how many impressions I got. But anecdotally, I got 20-30% more interactions than I’d get through organic alone.
Thus, the paid boost likely reached folks who were slightly less likely to engage, since the newsfeed algorithm organically already does a great job.
My buddy Kevin Mullett experimented with the promoted posts when they first rolled out. He notes they supposedly last for 72 hours. Mine lasted for only 12 hours, perhaps because I have 5,000 friends and can use up the impressions faster.
What percentages have you observed when you sponsor a post? Do you get a greater ratio of paid to organic impressions?