This post gives you a very interesting take on how to get your members in a personal place where they are able to truly engage with your association. Personal happiness and fulfillment is an interesting criteria for member engagement.
Throughout my career in association membership I have never been a real big fan of Member-Get-A-Member campaigns. I see too many ways they can go wrong and know other recruitment techniques that are more effective. That said, I do think they can work in the right situation and this post gives you some good recommendations on how to make yours succeed if you do one.
Think corporate entities are always ahead of associations? I don't but I do think they do some great things that we can learn from. This post gives you an idea of how for-profit companies are using membership to their advantage.
I am sure you have heard about Inbound Marketing as it is becoming more and more popular. This post by Tony Rossell does a good job of giving you some ways to bring people to you as opposed to you always reaching out to them. One thing he says that I really like is that Inbound is an addition to your marketing plan, not a substitute for the more traditional sources.