Don't let them kick sand in your face or push you down on the playground.
You know the ones...they fold their arms and tell you that your community will fail unless it's on Facebook, or that you MUST have a Pinterest page, or that every human on earth should start their own forum because forums rock.
It's simple. Don't be bullied into using social tools that don't suit your online strategy. Use the right tool for the right job, and you're set.
It's not an either/or for social tools
You don't have to "choose sides" when it comes to Facebook vs a private community, and you should ignore anyone who tells you otherwise. All technology is merely a tool that will either help you achieve your goal or not.
Ultimately, the best answer is often both. Facebook, Twitter, and LinkedIn for outreach and networking, plus a robust platform on your own home base. That's a powerful one-two punch of open communication.
Build your community based on strategic goals
If you are investing time on a specific social tool, do you know why? If the answer is that someone told you that you HAD to be there, it might be time to re-evaluate.
Take a hard look at your business goals and figure out how that time spent is supporting them.
But don't let me bully you.