Pipe tobacco and cigars are quite different from cigarettes.
With pipe tobacco you're getting: tobacco.
With cigarettes you're getting pretty altered nicotine in free-base form, which hits you much faster and thus is more addictive.
The speed at which a drug acts is directly proportional to how addictive it is, and cigarettes have much more free base nicotine (absorbed much, much, much faster), about 35 times more free base nicotine than naturally occurs in tobacco.