The advantages to nic shots are, your able to try 0mg and can add nicotine if you feel you need it. Before the TPD came in, 100ml bottles were the maximum sized bottles you could use. By adding nic shots you can now get 120ml, an extra 20ml. By using a 120ml bottles, the juice tends to last that little bit longer and is cheaper in the long run. When adding nicotine you can add up to 6mg if you need a stronger hit and also decrease if needed. By buying a bigger bottle, like a 100ml or 120ml bottle and adding nic shots it becomes so much easier than carrying around lots of 10ml bottles. Nic shots come in different styles free based nicotine, nic salt shots for a more intense hit and ice/cool shots if you like to add more menthol to your flavour.