I have limited internet connection where I live and I use a slow link. Periodically I want fast internet connection and I got a Go Phone WiFi Hotspot. It does exactly what I need, BUT, in the span of 1.5 hours I used almost 1GB of usage of my time and that was expensive. I only checked bank sites, messages, used the Safari for about 1 hour and then checked my usage and I got zapped for 1GB. I watched the Data stream using the activity monitor and saw the MAC sending and receiving data with background housekeeping, etc. and then I turned the WiFi off ASAP. I want to use this as an emergency type of thing since in a power outage where I live I have landline and dial up access and I can use this HotSpot as an option as well. But all the time would be very expensive. I want to manage the machine more carefully.