Nicotine salts (Nic Salts) is a nicotine form that is naturally occurring in tobacco leaves. Instead of only containing isolated nicotine, nicotine salts contain other organic compounds found in tobacco leaves. Due to its biocompatibility, vaping salt based nicotine (nic Salts) means than unlike high strength e-liquid, higher nicotine levels can be vaped without throat irritation.
Nic Salts are ideal for the high nicotine strength users as they find it more satisfying than regular e-liquid. 
Nicotine salts allow you to vape higher concentrations of nicotine whilst consuming less e-liquid which also makes nic salts more cost-efficient.
Simply put – nic salts give you more bang for your buck.