Is "Reach" of a particular Facebook post "public"?

Question

I've been searching through docs but can't find a definite clear answer.

The Likes,comments and shares of a particular Facebook post are public i.e. If i query via fql the summary(insights) of a public facebook post from any random public facebook page,it would return the likes,comments,shares of that FB post.

I 've been trying to know "Reach" of a particular post of a random public facebook page,but in vain. Is it known only to Facebook page admin/owner?

Answer 1

You can get the impressions of a post with the following query-

SELECT post_id, actor_id, message, impressions FROM stream WHERE actor_id = {owned_page} and source_id = {owned_page}

But yes, you need some permissions- manage_pages, read_insights, read_stream etc. to fetch the impressions.

Here I've explained the same in detail.