This might sound like a nit, but I'd call it habit-forming, not addictive. I watched friends go from obsessed with Facebook when it launched to mostly using it

This might sound like a nit, but I'd call it habit-forming, not addictive. I watched friends go from obsessed with Facebook when it launched to mostly using it for sharing family photos, and this is at a time when there was a focus on user engagement. It just seems like people lost interest too easily for it to be actual addiction.