Best Method is Face to Face
The best method continues to be a face to face where a board or supervisor hears first-hand the enthusiasm of the accreditation advocate and gets to pose questions regarding their concerns.
It is often good to seek out an accreditation advocate from the board of a similar organization. Board members feel confident that another board member understands their particular issues and concerns. It can be just as successful to match the attitude or perspective of the board with the advocate. For example, if a camp has a very corporate board, a good advocate might be the executive director of a highly credible for-profit camp in the area.
These same principles apply to convincing a supervisor of the value of accreditation. Call your local ACA office  and ask for assistance in locating an appropriate advocate.
Research other Accredited Camps
You may locate valuable (convincing) information by assessing camps similar to your camp. Use ACA's Camp Database  to learn a lot about accredited camps across the country. There are 11 different ways to search. You will be able to locate camps with similar . . . clientele, activities, sponsoring organizations