For me, I found that it was my excitement and passion of the game that sold the idea to my friends. Some bought packages right away well others felt there were too many unknowns for them to make an investment.
My advice would be, just continue to express your excitement about new things that are coming out and eventually they will feel more secure about the game.
Everyone has different levels of risk that they are comfortable with, which results in some needing more assurances then others.