As I speak with individuals about the goals for their community, inevitably I aim to understand what primary problem he/she is attempting to solve, and for whom. If the responses become too generic, I tell them about my lesson learned from a garden hose.
The nozzle of most all garden hoses typically enable two extremes: One that widens the water stream to a near mist, and the other focuses it into a narrow jet. Imagine yourself hosing down the side of a house that's covered in dirt and grime. If you adjust the hose nozzle to mist, you will indeed hit a wide area of the wall, and you may even hit every corner with some droplets of water. But if the goal is to knock dirt off, your efforts will not be very fruitful. However, if you focus the stream to a narrow jet, then you're using the same amount of water to hit a much smaller area on the wall, but you are likely knocking that dirt right off.
If you want to make an impact and get something accomplished, focus your efforts. It's an alluring trap for community builders to attempt to be everything to everybody in exchange membership growth (which I've warned against in an earlier blog post). People are more willing to join a focused group with a specific purpose that can create a real impact. Communities with such focus may grow slowly, but they grow with the right people involved. And in my opinion, nothing has a greater organic attraction than a community that is making an impact. Focused efforts create that impact, not wide sprays.
You only have 24 hours in a day, so completely annihilate one problem versus dampening a yard of them.