I have a dot info and dot com extension for the same name. I first purchased dot info because it was cheap. however, I was afraid that someone might use dot com, which is more trusted, so I redistered dot com as well. I also had many cheaper alternatives of dot club and dot online domains, however, in the second year I did not renew those domains because it was more of a financial obligations. If your website has potential to grow big and create a brand that is easilt identified, having other extensions is really useful.