What do people like on online communities?

As mentioned before I never thought much about online communities. Now while I´m participating for a while in the community psd- tutorials I start enjoying it. I already found many interesting information that were really useful for me and my design work.

While we were discussing in our team about how we could motivate people to participate I recognized a difference. On psd- tutorials people talk about their hobbies, their common interests. This is a big difference to our communities, where we want people to talk about their own problems and very personal subjects. While my sister were busy with organizing her wedding she joined a community weddix.de to find tips about a perfectly organized day. Now more than two months after the wedding she still participates in the community daily. Now she sometimes gives tips to futural brides, but most of the time she posts in off-topic threads.
I asked her why and she gave me the following answers:

- In your own environment not everybody has the same interests at the same time (wedding). This was the reason why she signed in in the community.
- She is still a member, because she met there people she is regularly in contact with
- The Community growed and has now many subcommunities. It startet only about weddings but now there are also topics like honeymoon, building houses, children, holidays, cooking, swine flue…
- It is another sphere talking with other members than meeting with real friends

I hope this information can be useful to you all, when you think about motivating people to become users in your community.