I wouldn't consider biuying data as something that is usefull to ditch, like the starbucks situation is. When I lived in the caribbean buying data was the same as by you, something that had to be don and was expensive. But on the other hand, look at in how many ways it brngs you stuff. Not like netflix, but also in the option to learn stuff, surf around and stay in touch with other as well.
Getting data seems more like something usefull. I guess it is more the ditching buying the chocolate bar at the gas station that goes along with buying the data :D
But indeed...looking at all of the small purchases does really help in the end.!