Everyone gets all worried about the extension they give to their website. People worry about acquiring a dot com site, while others are fine with getting a dot net or a dot org. While it makes more sense for an organization site to use .org, it can be used by any kind of business without any issues.
The reason why we have so many extensions is because dot com was running out of options. The market was saturated and new extensions needed to be created in order to allow certain words and word combinations to be used again. They all have the potential of becoming big and popular if you work hard on maintaining content quality.