Smokeless Cigs?

I recently saw smokeless cigarettes. Just when I think I've seen it all. I don't know a lot about them but know they use clove vapor cartridges and don't have real smoke. I am not sure if they use real tobacco or not. Whether they do or not, what is the appeal or need for someone to use vapor? Do they have a need to see "smoke" come from their mouth? Maybe it is a psychological thing? Either way, very interesting!