In previous posts I offered some suggestion for streamlining the sign-up process. But often an easier sign-up means skimpier profiles, at least at first.

So how do you encourage new members to build out their profiles?

Well, when we meet someone new, we tend to ask questions as a way of finding out more about them. Profiles are really just answers to questions. So a great way to help members create full, rich profiles is to ask them questions about themselves, or about whatever the focus is of the site: What’s you favorite wine? What was the first item in your collection?

Don’t shy away from making the question a bit provoking: Strong opinions generate interaction.

The answers to these question can becoming a growing part of the member’s profile.  The questions could be the same five questions all members get asked the first week they join, or you could pose a new question for all members each week, and post the responses. You can even let other members give a thumbs up (or down) for originality.

These questions can bring members back to the site if you send them out by e-mail, or you can ask a new one every time they log in. You could even let members ask each other specific questions with a single click for a low-friction way of starting interaction.

If you display the best answers on the home page it can tap into the sense of community and pride and encourage participation as people aim to get their clever answers featured.

The social site Consumating (since shut down) did a great job of encouraging engagement by asking questions like these, and posting everyone’s responses so other members could give the answers a thumbs up or a thumbs down vote.

More recently, Plinky has a similar model for “content encouragement.” They pose a question every day, that people can use as a starting point for a blog post.

After all, questions are the foundation of Facebook (“What’s on your mind?”) and Twitter (“What’s happening“).

That’s a smart strategy any social network can use to encourage full, revealing profiles or even fresh blogs, status reports, and more.