People will usually line up or even mob you to get the 'free' gift . Literature is non-threatening. Some cultures and peoples' personalities do not respond to confrontational evangelism. Some people are shy or scared to talk about their feelings but will listen if God speaks to their heart. The Spirit still supernaturally calls people.
Literature evangelism is considered friendly and often leads to discussion on a one on one basis.
Using gospel literature means never being sidetracked by rain, snow, electricity. When you are gone the work lives on. It crosses cultural and language barriers with truths that can be misunderstood when spoken. If the address of local believers or churches is located on the piece it often leads to contact and further discussion for future follow-up. One very effective way of 'going into all the world', is to use gospel tracts, booklets, Bible portions and leaflets to present a clear message to individuals.