Since I've never had unlimited data (except once, as a dealer, in the days of 1G - which meant downloading constantly for 24 hours wasn't much data), I rarely use 1GB/month. Most of my data use on my phone is wifi - which I have an unlimited amount of almost anywhere I am. Since, as mbkinter has, my phone connects when I'm where any of my secure wifi signals are, I probably wouldn't use much more data if I had unlimited. This month, with 5 days left in the billing cycle, out of 12.4GB avilable (rollover), I have 10.1GB left. And that's with 2 kids who are on the internet regularly - text doesn't use much data, and most of the sites they use when out and about are mostly text.
If I had unlimited data and tethering, and could get live TV on the phone, I'd probably drop my ISP completely and use at least 100GB/month.