The Infinite Warfare beta is about to start this weekend, and if it works like the Black Ops III beta did, people should be getting more than one beta code for signing up. If you find yourself with an extra code, feel free to share it here. The beta starts this weekend on PS4, and will continue next weekend on both PS4 and Xbox One.
The beta is free with a pre-order. If you pre-order online at Amazon or something, you should be able to cancel your order if you don't care for the beta, so there's no real risk here. If you still don't want to pre-order, watch this thread for extra beta codes. If this beta follows the precedent set by the last COD beta, you very well might be able to get in without a code towards the end anyhow.
 The beta is now open for all players on PS4, no code required. Xbox One users now also have beta access, but codes are still currently required.