Every time you use smokeless tobacco your body adjusts to the amount of tobacco needed to get that high. Then you need a little more tobacco to get the same feeling. You see, your body gets used to the chemicals you give it. Pretty soon you'll need more smokeless tobacco, more often or you'll need stronger spit tobacco to reach the same level. This process is called addiction.
Some people say spit tobacco is ok because there's no smoke, like a cigarette has.
Don't believe them. It's not a safe alternative to smoking. You just move health problems from your lungs to your mouth. Cancers most frequently occur at the site where tobacco is held in the mouth. When you hold tobacco in one place in your mouth, your mouth becomes irritated by the tobacco juice.