I like the idea of this kind of a business and here is why.
1. It is a business that nearly anyone can be a customer for. Most people take showers or bathe in some manner and use soap in the process so anyone is a potential customer.
2. It's a business that can be done on and offline. I like this because I don't want to spend my life in front of a computer. I like to meet people face to face.
3. It feels legit to me. Not like I'm tricking someone into buying something that I know that they don't really need or is really not going to deliver what a promise for whatever reason.
4. It's portable so if I want to take a road trip I can bring the soap with me and perhaps meet new customers on the road.
I'd love to hear some other ideas for businesses like this. Along with the soap business some obvious ideas would be shampoo, lotion, etc. I'd love to hear other ideas outside of this.
I'm really looking forward to hearing what you brainstorm.