You know, pixel, that is just the opposite approach to what we took. To have issues brought up at church or at family dinners or other social activities spoils both the business and the socializing. If we contacted people because they are members of the same PTA as us, then the PTA refreshment breaks can become a venue for gripes; if the person who becomes a member of our CSA happens to be a member of the same PTA, it is a one on one discussion and doesn't involve everyone there. At least that was our reasoning. We've also supplied farm products to our family since forever. It's hard to discuss charging your aunt for the tomatoes you've previously given her.
We found that by beginning with acquaintances, such as summer people, we could establish the CSA as a BUSINESS. Then if friends and family want to join, they are joining a business, not changing a relationship. Again, at that time we had an established farm stand business, so we had a venue for getting the offer out with each sale. Had I been starting up from my own personal garden patch, my opinions and my options would no doubt be different.