I have been a Verizon Wireless customer for 17 years. Currently, I have 5 lines: two 3G iPhones, two 3G Android phones, and one dumb phone.
With four 3G devices, my data usage fluctuates between 4 and 6 GB.
Note that 4 to 6 GB is the size of a movie on a video DVD.
More than half of this data is pushed or pulled by system services and by advertizing network services integrated with applications. Even replacing basic ad-supported applications with non-free versions (in the hope of reducing the share of advertizing in the overall data usage) - even this does not help much.
The smartphone devices used by members of my family are aging. The newest of them was bought in September of 2011, and other devices are older.
If and when one of these devices is replaced with a 4G device, data usage will increase significantly because of system background services, ad network services activity, and user tracking. Seemingly, I cannot abandon my grandfathered unlimited data plan. I can't pay the grossly inflated full prices for new devices either.
Undubtedly, Verizon Wireless does not value me as a customer. Time to switch to another carrier.