One of our forum regulars, Glass, used Rubbernet to measure how much data he was sending and receiving while playing the Diablo 3 Beta. The program gave him precise measurements of how much bandwidth the game uses, and in his forum post, Glass shares the results.
The verdict? Surprisingly little data is exchanged during play, even during a four-player game. Much less than you’d use doing almost anything else online, including checking email or surfing.
Check Glass’ thread for additional screen caps that show the exact stats. This seems like good news for players with slow connections or a limited bandwidth allotment. Especially since just playing single player is not an option with Diablo III.