I wasn't sure of what this provided until I opened this on a home connection and it showed a subnet where I wouldn't recognize the other people at all (this is with ISP assigned IP addresses). For home use, I'd be thrilled if something were available within the home router's internal address range, rather than an external IP.

Even in offices, I guess this would be useful in very small environments. Even medium sized networks could have subnets where people within a single subnet may not recognize one another or want to be in a single chat room with a stranger.