Over the span of my short career, I have had numerous requests and promises made to me by people with very friendly personalities. However, when push came to shove, either those promises were broken or requests had a lot of hidden features. When asking “why,” I was told more or less that nothing was in writing, therefore anything goes.
Getting something in writing protects you from these kinds of pitfalls. Having a written document, signed by the promisor not only ties him/her into making good lest you take them to court, but also lays out a guideline of items to do in case there is confusion between both parties.
Get it in writing. I can’t stress this enough. What is mentioned behind closed doors stays behind closed doors and cannot be proven when brought up again. If it ain’t written, it ain’t.