I signed up for the free prime trial during the Christmas season this year and let it lapse (didn't cancel it) out of apathy. Granted, I use Amazon enough where it probably makes sense. Without prime I would often purchase additional items to qualify for "free" shipping. With prime, however, I make more impulse buys.
I don't use any of the other prime benefits besides shipping.
Anyways, I probably can't justify $120 a year even though it is not really much more than the $80 I am paying now. I believe when prime first came out it was $50.
When I signed up for Prime 6+ years ago, I felt the same way. I was hesitant to do it, and I expected to cancel it after my free trial.
I still have it, and I've never let the service lapse, because I now do the majority of my shopping on Amazon. I buy everything from cat food to toilet paper, and I buy a lot of things (like DVD/Blu-ray) that I never previously had the motivation to go to a store to buy or that I don't have the ability to transport (like shelving units and chairs). It's supercharged my hobbies (electronics and 3d printing), and saved me days in back-and-forth to stores.
So I suppose I'm one of those customers that can easily justify the $120, and would be more than happy to pay more, especially if it means that Amazon will put a little more effort into faster delivery.
I don't use any of the other prime benefits besides shipping.
Anyways, I probably can't justify $120 a year even though it is not really much more than the $80 I am paying now. I believe when prime first came out it was $50.