I mean if notifications are the primary feature (being connected 24x7 etc), isn't that the purpose of a smartphone after all? Why bring yet another device into the fray when it admittedly is a one-trick pony at this point of time?
My job is to give people I'm in conversation with my full attention. Getting texts or whatever used to completely destroy my ability to concentrate, and they are almost always useless — but not completely, preventing me from turning them off. With my Pebble, I can casually stretch and glance at my wrist to make sure that the house isn't on fire, and my client has no idea.
Likewise, I've never had a phone that vibrated strongly enough to get my attention when walking or biking. This is usually when all of the important calls would come in. Now the problem is solved.
Is it revolutionary? Will it change your life? No, I don't share the same rosy view as the parent commenter. But I do find it handy, my phone stays in the bag most of the time, and I don't have to dig for it to find out that I need to pick up milk on the way home.
Also, I had an app which forwarded all phone notifications to the Pebble and it certainly helps you realise just how spammy the phone is. But it was useful for capturing things like bank app alerts, TripIt, Google Now, etc.
When I am home I can also walk around the house and get alerts without having my phone on me which was also a surprise use case I hadn't expected.
Count me as reformed; I fell in love with the Pebble quickly. Now I won't try to tell anyone that it is a do-all device but it has done two things for me.
A. Having notifications pop up on your wrist... priceless. I get email and texts constantly and when I am working on-site I don't have to keep pulling out my phone. I can assess quickly if it's something I need to take time to deal with. I now wonder how I did without this.
B. It has convinced me that this is going to be a very big thing in the future. I find I constantly want the Pebble to do more... like the Galaxy Gear does. I'm not advocating the Gear specifically, but I am saying that having a Pebble has convinced me that this is a mobile device interface (wrist mounted) I want to see mature and that I will be making a standard device type for me.