Think about what would happen if THOUSANDS of dive resorts and shops around the world shared information on new divers? think about how many new divers might still be diving and spending money today, and attracting friends to dive with them near their homes if a shop had referred them? and if one of the local shops who was referred bothered to make a call and INVITE this new diver to their shop or on a club dive in the near future? I can tell you that it works.
Dive trips aren't easy, but that's because most shops only sponsor the bigger trips to distant and/or exotic locations. But the dives that really get people active and keep them diving are the local dives, and sometimes that means owner, instructors, and DMs doing a little advance work and maybe even diving a body of water rarely considered by local divers. I realize many LDS do have local dive programs, but I'm saying the way to keep divers active is to give them options. And options that can compete economically with the other distractions of life. It may also mean that an LDS needs to work closely with a local travel company. If you keep your divers active, eventually they want to plan to attend one of the bigger trips. If every trip is filled for two years in advance (see scubaboard invasions) you aren't going to retain many. But if you keep options open, plan a 10-12 person trip every 6-8 weeks, people tend to migrate to those things, and maybe you have to drop a trip because everyone is dived out, or discount it, or promote it with an equipment give away... if you have 8 trips running a year with 10-12 people, out of one LDS, you can afford to promote them now and again.
Same with regional activities. Imagine if groups of LDS in different areas of the US traded activities and did joint dive activities?