I am not totally sure, but I believe that this is only important to link two tabs in the browser together… for the publish/subscribe (but I could be wrong). This allows you to right click on one item (part number) and open the part screen, and then those two screens are linked. The part on the second screen will change. My theory is that the channel is how we keep these two linked together.
ADDITIONAL INFO ADDED:
CONFIRMED my Theory… the Channel ID is how we keep two publish/subscribe screens linked… we make each one unique so as to not cause unknown behaviour. WE have tried it set to zero, and it works, and have not seen anything if you do so, but you can/should set a unique value… even if just a random number when creating a new deep link.