We've been a member of the local home builder's association in Quebec (APCHQ) for several reasons. The association has some nice discounts on things such as telephone and internet services, supplies at certain retailers, etc. They also have excellent basic training courses which are good for new recruits that need to be brought up to speed. They offer another avenue for marketing ourselves (web-site and publications), and also help with regulatory compliance (ie, interprete the laws and advise us what to do). The networking opportunities are good as well. And it doesn't hurt to be able to show their logo to prospective customers as part of us establishing our legitimacy. We're fully licensed, insured, bonded and these affiliations help us distinguish ourselves from the contractors who work under the table.