If you want people to interact more with your content, show them that you care about what they have to say and what they do, make their voices heard.
Consider this example. A friend of yours shared a blog post he liked via Facebook. You bookmarked that for reading later or just left the blog post open in a tab to come back later to read it.
When you did come back to reading that post and even left a comment there, your friend will want to know what you thought about it. But chances are you now don’t remember where that link come from, or just wouldn’t want to go through the trouble of repeating what you think of the post to your friend.
Another frustrating example comes from Facebook itself and the likes of it. I shared a picture found in some Facebook group. The picture already had some comments and likes, but what happens now is you my audience can comment and like my “share”, separately from the comments and likes that picture had in the first place. But the likeliest thing to happen is them opening the image I shared, liking and leaving a comment within that full view dialogue, contributing to the original content provider and me never knowing what happened or how friends reacted.
It’s like if you want to comment on any content on the web you might have to do it two to infinite number of times for everyone of your friends to know what you think about it.