I wonder the same, but then I seem to be quite a different consumer than those who post here. I don't play games. I don't download music. If I want to watch a movie, I go to the cinema and enjoy sitting in the dark while eating popcorn. I watch TV shows on the "gasp" TV from my satellite service. I spend 4 - 6 hours every day on the internet, mainly following news items (a lot on /.) I watch videos associated with those news items when I want. Sometimes my wife watches the same videos, which costs the data transfer again. I do automatic backup of both computers to the cloud. And all my landline phone usage is VOIP. I use about 25GB per month.
Streaming video services are just almost beginning to be available in NZ.
Here in NZ, we have limited choices I guess. There are quite a few ISPs, but they generally are reselling DSL services on lines owned by the telco. My speeds are ~12 Mbps down, ~1Mbps up. Almost all providers have data caps, either going to dialup speed or $$ extra when the cap is exceeded. I chose one that had no data allowance at all. I much preferred just paying for what I used at NZ$1/GB plus a base monthly charge. I am quite happy with that.