Walking ads
T-shirts are basically mobile ads. They make your company a lot more visible, as customers wear them anywhere, spreading the word wherever they go.
Visual appeal
There needs to be a great focus on quality. If you have a quality t-shirt with your professional logo and a message that resonates with your audience, it is bound to cause a reaction.

Conversation starter
Conversation opener If your shirt makes a statement that others can relate to, they will want to talk to you about it, and learn more about your business.
Cost-effective
One of the most cost-effective marketing techniques, Get your own custom t-shirts that represent your brand and carry a message that will resonate with your customers and gain their interest.