Sorry for the delay, life got in the way.
Short answer. groov, at the moment, does not have a community string.
It also does not have a way to directly monitor its bandwidth.
If you are running groov server for windows, there might be a program that will give you that information.
If you are running on a groov Box, other than a router or a managed switch, we have nothing to show the data use.
In general, its a good question, and the the answer is dependent on what tags and gadgets are on the page and how many clients are viewing each page.
10 text gadgets with one client, not so bad.
4 HD video gadgets and 10 clients.... ooooo, better have deep pockets for that months data usage. (An engineer that may or may not work at opto may or may not have left for the night with his browser open streaming said 4 HD cameras allll night streaming over a 4G cellular modem).
Best bet. Managed switch. Pretty cheap these days and you can get all the data you need via SNMP.