This is not an unusual scenario Chris you'll find it with most of the magic societies and even local magic shops (back in the day), who would send performers out on gigs. It's just a branding point in that from the marketing world's point of view, it is known that the average consumer buys into the lie of a label. Brand X that has no association with any reputable organization that is "known" to the general public will not be used nearly as much as Bran A that carries with it "endorsement" by this and that organization.
Networking is the key to any business and within show biz, if you have the logos of the Magic Castle, IBM, PEA, etc. all on your web page people are more inclined to buy you. You'll also notice how some performers work in the name of the schools they've attended and even the Fraternity or Sorority they belonged to... it's so as to create (and exploit) kinship connection and stimulate the old idea of "supporting one's own".
These membership alliances can go much further, including the local Chamber of Commerce, the Better Business Associations, and civic groups such as the Jaycees or Lion's clubs (or those evil Free Mason's groups).
It's all business! Literally a means by which to direct the "drive train" (consumer) your way. It's a horrid part of life and reality.
