Do

Cultivate a presence on multiple social platforms
Think about where prospective members will be: Facebook? Twitter? Google? MySpace? StumbleUpon? Niche communities? Choose platforms where you think you can have the biggest reach. Join them, create a profile or page with thoughtful messaging and obvious links back to your Ning Network, and begin to cultivate a positive reputation on these platforms.

Share compelling content
On a regular basis, identify the best content contributed by you or your members and share it on Facebook, Twitter, Google+, StumbleUpon or other platforms. If you haven’t already, set up Twitter and Facebook integrations so content shared from your Ning Network will display your branding and will link directly back to your network.

Encourage members to share
Include instructions in your welcome box or page. Suggest sharing when you welcome new members. Barista Exchange sends out broadcast messages letting members know about the social media tools available to them. Add Facebook Like and Google +1 buttons to your network to make it even easier for your members to share content on these platforms.

Send a personal email to invitees who haven’t joined
Send a custom invitation to all of your outstanding invitees from your personal or work email and include the invite link. Invitees are more likely to open a personal email from an email address they trust. If prospective members are less likely to use email, message them on Facebook. Or text them. Experiment to find out what works best!

Encourage members to invite others
Make a personal appeal through a broadcast message or private messages. Members will benefit by bringing friends or colleagues into the conversation. Make sure you explain how to use the invitation feature and specify which types of people to invite. Manny Hernandez from TuDiabetes provides members with postcards they can give or send to prospective members.

Recruit offline
For many Network Creators, offline recruiting can be the most fertile source of new members. Create business cards or flyers with your network name, URL and description. Hand them out at trade shows, conferences, concerts or other events. Matt Rodriguez holds a basketball tournament every year and promotes his network, BallIsLife, at the event. The Barista Exchange hosts events at local coffee shops.

Collaborate on banners, buttons and links
Identify related blogs, forums and social networks. Offer to repost their content on your Ning Network with links back to their site – in return for doing the same with content from your network. By “bartering” banners, buttons and links, you’ll improve your search ranking and attract new members.

Tell visitors what to do
Yes, it’s often that simple. A great example is the welcome box on Lifeafternewyork.com. Don’t wait for visitors to figure it out themselves. Start a discussion topic they won't be able to pass up. Use the Quiz Ning App to challenge visitors and see if they can ace it. How about giving your members a chance to win a giveaway by simply posting a photo? There are lots of ways to encourage lightweight participation.

Don't

Forget to engage current members
Your current members are your biggest selling point to prospective members. They contribute compelling content and are your best promoters. Review Make Your Members Stars for valuable ways to engage your members.

Go overboard with promotion
Brett McKay, who built the Art of Manliness, advises: "One mistake I see many people on the Web make is that they promote every single piece of new content on their site. It's overkill, and you may be setting yourself up for people to ignore you. If you want people to come to your Ning Network, put stuff out on Facebook or Twitter that's click-worthy."