You can use t shirts to do many other things apart from just getting to cover your body. For instance if you are in some kind of business and you probably want to advertise your business or the products which you are offering then you can use t shirts to convey your message.
Advertising your business and the products that you have to offer using customized t shirts offers a business numerous advantages compared to the use of other advertising systems. For example as a business person you will get to use a very small fraction of your advertising budget in getting customized t shirts made for you.
Because your t shirts will be worn by people then you will be able to get your message to many people. Basically your message will be conveyed in a better way as those who are wearing the t shirts will be able to provide some additional information to those who seek for any clarifications.