I can see where John's coming from. However, my experience is that ASIS is as good as you make it. Building up your local chapter by participating in leadership, getting speakers to discuss topics relevant to security integration, etc. have a big impact on the value of the organization relative to time and money spent.
I've used the annual ASIS show as a way to keep myself and clients up to date on products and trends. That noted, ISC West has taken the lead in that respect.
Networking both locally and nationally is another reason I've participated in ASIS...Again, you get out of it what you put into the organization.
As a note, I earned my CPP before ASIS came up with the other designations. It was a difficult exam that required a decent amount of industry experience just to sit for the exam as well as a lot of studying in order to pass the exam. Since that time, I've done a lot to continue to grow my security career. However, I did not keep up with the ASIS CEU's. It's disappointing that ASIS does not recognize a wider range of education to keep up certifications. Since earning my CPP in 2003, I've earned my law degree along with other technical / product certifications. Still, I can't get ASIS to recognize my designation.
There are other organizations such as the International Organization for Healthcare Security and Safety. Again, you have to invest time to benefit from the association.
Others to consider include
NSCA - National Systems Contractors Association
ESA - Electronic Security Association
One thing to consider if you're looking to use an association for marketing purposes, groups that are related to the security industry are likely to have some if not many of your competitors. To connect with customer prospects, trying connecting with other industry related groups.