I would add to some of the comments above the following...
1). Promote and give a s**t about events and disciplines outside of the olympic disciplines and sporting. There are thousands of shooters out there dedicated to their chosen discipline who attend majors where in effect it is no different to a standard registered Sunday as no effort was put in.
Sure i accept that one is the biggest participant discipline and the others carry with them the "prestige" but even so that does not mean that other disciplines should be ignored.
2). Get over the fact that kids with wealthy parents are the future of the sport.... utter nonsense IMO..... you want to increase participation then you need that no kids, good income group OR grown up kids, still working group.
3). Be at and visit grounds that are NOT holding registered. Surround themselves with those every week shooters who go to their local club and spend similar money to registered shooting but just shooting. Find out what it would take for those grounds to "go registered" and take their regulars along with them. Maybe even supply / volunteer to do X number of events for them coaching and guiding them on how to fill in shoot reports / submit scores. Show the shooters and grounds its not complicated... show their customers there is nothing to be afraid of by registering scores and shooting competition - tell them about birds only and such like.
Harsh truth is by vendors and associations being at majors they are in a very limited market which is all too often already equipped and does not need what is on offer. Once you have your kit how often do you upgrade or renew? Focus needs to be on that "not involved" sector but who still shoot - find that way to grab them.
4). Team up with and work with the various other associations..... so maybe have a "cross membership program" where by if you join us we also give you access to X association for the next 12 months. Instead of seeing other associations as competition learn to work together!
eg:- a). Did you realise that if you join our association it gives you insurance which you could then use to enter FEDECAT events - here is a flyer for them.
b). Ah sir / madam you like skeet? Did you realise that you could get into NSSA skeet aswell. Here is a flyer for them that gives you 12 months free membership to that association aswell when you enter an event. A few of our CPSA registered grounds offer both on the same day. Have you heard of the English Skeet Club - they offer events under our registered banner aswell. Here are some details. Did you also realise that there is also Olympic skeet and this is accessed through the BICTSF and British Shooting - here is some details about them. There is also the One Hundred Straight Club -........
c). You prefer sporting - have you heard of FITASC and NSCA - they offer ......... here are details. Thisis how you can get involved.
TBH it is not frigging difficult but everyone is so damn concerned about keeping their slice of the pie that they forget shooting is so intertwined and there is so much potential for growth by working together instead of trying to oppose each other all the time.