What if your marketing company ran an advertising campaign that promised to double the customers business and based it on the X squared dot biz domain. It would certainly be memorable. Domains don’t come any shorter. You can do lots of different graphics around the X squared theme.
This domain expires in October 2022. It was first registered in 2006.
What can you do with a domain like this?
X2 is as short as you can get. Use it when faced with serious length limitations.
Use as a link shortener is the obvious use case.
The dot biz TLD is not a big issue in the link shortener use case.
I use a three character domain for my email and it has saved me thousands of keystrokes over the years.
The first part of this video has a really wonderful description of what a link shortener is and does.