There are many bennies that come along, to much to list all. Being a CA has helped me tremendously, not doing anything different than I was before (was initially trained by a CA from Davey) but that cert has opened doors. TCIA is a great org, their mission, IMO, is to rid the world of tree bubba's. They both have helped me become more desirable to the customers that I want. Its a little pricey, but money well spent. The main thing they both do, is add to your credibility as a professional Arborist/Tree Service.
Many guys don't like the, in their words, good ol boy clubs. I don't understand this. If your in business to make money, then anything that helps you become more legitimate, to me, cant be a bad thing. When ya get the box from TCIA, it is like Christmas mourning, could not believe the amount of stuff they sent!