I use iMessage everyday since it came with iOS 5. My friends have iPod touches and wifi only iPads. We can only use 200 texts messages which isn't enough. Most of the time we are on wifi. So iMessage keeps us in contact without using an IM messenger or Facebook messenger. Since you asked if its worth it or not. I will say if you have many friends with an iPhone, iPod touch, iPad or a Mac on 10.8+, it is completely worth. You can text each other for no cost and plus you can make a group chat so you can talk to all of your friends in one group instead of switching to different chats.