LPT Get a port out pin from your big wireless carrier and they'll instantly give you a discount for fear of leaving them.
I went to change cell phone carriers from Verizon to another company today. If you want to keep your existing phone number, you have to login to your account, go to security, and click "request port out PIN number". You need to give this PIN number to your new carrier in order for the phone number to be moved over.
The only reason anyone would ever request this PIN is to change cell phone carriers. Thus, as soon as I asked for the code I got an email saying "Thanks for being a loyal customer. Here's $20 off your bill every month for a year!" I hadn't made the switch yet, so I could've just saved $240 just for thinking about it.
All it takes is you requesting that code for them to give you a discount for fear of leaving them. I imagine AT&T and T Mobile have similar practices. Go ahead try it! #entertainment