This certainly depends on your definition of "big data eater." But a standard Windows 10 installation DOES use data in ways that some users might not expect: unscheduled software updates, P2P seeding, etc. Also, the Windows 10 download itself is about 3 GB.
If you already know this or you live in an urban area, it may not be a concern for you. But it is for many of our customers. We will continue to address ways people can manage their data as Windows 10 continues to roll out and evolve. Here's more information for those who are interested. Thanks, Exede Matt