Okay so Ima take a quick educated guess. And you seen a hotspot with the name XFINITYWIFI, Comcast gives you a complimentary 1 hour access. But here is the trick...
If you change your MAC address you can get UNLIMITED 1 hour complimentary sessions.
1. Connect to "XFINITYWIFI" your gonna be prompted with a window to sign up. You should see that 1-hour complimentary session. Click on that and just put a random email and random zip code you can try: 90000
2. Once your complimentary session IS DONE. open up terminal and type in to get a generated MAC address.
-[ openssl rand -hex 6 | sed 's/\(..\)/\1:/g; s/.$//' ]
3.Now Assign it:
sudo ifconfig en0 ether xx:xx:xx:xx:xx:xx
Replace “xx:xx:xx:xx:xx:xx” with the desired MAC address
4. Hit return and enter the administrators password to set the new address. To confirm it has been changed, type the following:
ifconfig en0 |grep ether
5. Go on to system preferences > network > click advanced > and delete xfinity wifi from the known network list.
6. Click on XFINITYWIFI again, and repeat step one.
If your not being prompted open your browser, and go to xfinitywifi.com
Thanks,
at0m