Offline marketing - having my url on shirts

I think it really depends on what you are linking to as well. It's the same idea behind targeted marketing, if you randomly ask 1000 people if they need SEO service, you won't get far. However if you link those 1000 people to a time wasting site with games and such, you'll get some traffic and ad revenue. Probably not cost effective in any manner unless the people wearing the shirts are committed to showing them off.

But as stated above, it adds branding and pride.

 

Will it pay for itself, most likely not. Yet shirts are moderately cheap and since you have 6 employees getting people custom shirts + maybe even sweaters is not really expensive probably compared to your other costs, and will help you build a lot of credibility and help your business. In my opinion, once you start employing people, totally worth it!

 

I don't think it is going to make any significant impact on the traffic directed to your site. It will help in branding and reinforcing professionalism, a sense of belonging, pride and teamwork for you and your employees.

 

very smart and free advertising