I am a school librarian/technology integrator, and I can't justify buying this. The author made a huge, problematic leap at the end. In the ending, the protagonist suddenly grows from an elementary age kid to an adult who fails a job interview due to her online presence. What little kid cares about or understands job interviews? What little kid has the cognitive capacity to think, "oh yes, that's right, my entire life will be destroyed by being a meanie online"?
The story just ends, and that girl is just screwed. No learning happens, no opportunities for correcting mistakes, or apologies. That's pretty dark for a book aimed towards 1st and 2nd graders. I can't teach 7-year-olds that.
The story started fine, and I liked the concept of the tail. But, the story could've instead been about an interpersonal problem caused by the girl's reckless posting - which little kids would actually understand and have the ability to reflect upon.