Why don't people share on social media?

If you see these eyes looking at you with love, the first thing you do is want to cuddle with this gorgeous girl. Many people would only see her if they were searching through Petfinder. Her description is as follows: She is a 6 month old Vizsla mix who loves other dogs, toys and being near her human. She is in a foster home learning how to live in a house and would love to find her forever home.
I will share this column on social media and ask that anyone who sees this to share with their friends. One thing that is for sure about sharing is that it results in adoptions. People see a photo and want to know more.
My question is, "Why don't people share?" It only takes one click; they don't have to write anything; all the information is included in the blog but they still don't. Why is that?
So think about it and if you have an answer, please respond to the blog. In the absence of answers, please share Serenity. She needs a good home.
If you would like more information on her, contact Satchel's Last Resort and they should be able to tell you anything you want to know.
Thanks, and once again, please share.