The four things you should consider when choosing your domain name are:
The Human Perspective
You want a domain that’s simple to read, simple to say, and simple to remember. It also helps if it’s easy to type.
The Brand Perspective
You’re always going to want people to know what you’re about in the shortest amount of time possible.
Back in the day there were a handful of choices – .com, .net, .org, etc, and a lot of them had extra extensions depending on what country you were in.
Just about everyone is looking to rank well in Google to help all those people searching for exactly what your blog provides. If you’ve got a clever and funny blog name but it has no bearing on your actual content, then your URL is not going to be the first few options a searcher sees when they’re looking for what you’ve got.