First off, reading poetry essays reinforced the work my class did at the beginning of the semester and served as a reminder that learning/thinking about a particular genre is not over once that segment of the course ends. They also seemed happy to flex their literary interpretation muscles after working on a research-based essay for the past few weeks.
Secondly, my students realized just how difficult it can be to read someone's draft and provide constructive feedback. Seeing the revision process from this side allowed them to experience what it feels like to make judgments on a piece of writing and many said that it helped them read their own work with fresh eyes.
Finally, they seemed pleased with the feeling of authority the process provided them. I reminded them that you need not be a college professor to read and respond to an essay and this exercise brought that home for them. After a semester of reading, writing, and revising, they felt comfortable enough in their own abilities to express their opinions freely. Their feedback was also quite good, overall, and they provided Jeremey's students with thoughtful comments, constructive criticism, and encouragement.
The one minor difficulty was Facebook's inability to accept 20 or 25 posts at the same time (it's a drawback of doing this during class time). By now we knew this would be coming, though, so we were able to manage that fairly easily. Those who couldn't post while in class saved their work and posted it later.
Overall, I was quite pleased with the process and so were my students. I just hope Jeremey's class found the feedback to be useful in their revision process.