I'd agree with Trevor that you have to put in to get something back, and my own experiences support this many times over, and I'm not talking only about financial gains.
But there are a fewgreat jobs that come directly from membership. Last month I had an email enquiry via the NCCA website. A property company in Stony Stratford wanted an "Approximation" of costs for a 3 bedroom flat in my area (about 4 miles away). Experience tells me that this could be more than grubby (it was!). Estimate at my normal residential rate. Few days later I receive an order and did the work in mid December with instructions that the price was in the ballpark, but appreciated that it may cost a little more. My regular charge came out £233 and it was half days work, £7 below estimate. Payment was prompt as per agreement with a very nice complimentary letter from the client. This one job alone has paid a years membership, so everything else I receive is a bonus.
A newbie who I met at the NCCA Show's Dinner was due to shadow me that day, but was unable to make it (hows the tummy bug now Brock?) so there's another great colleague I've met via the NCCA.
My life is certainly richer because of my NCCA membership and involvement and, as a bonus, it is self financing for me.
Safe and happy cleaning

Ken