The forums change because times change, Facebook has grabbed a big part of the parkour conversation. If i post a video in pics and vids it will get maybe a couple responses and 20-30 views same video posted on facebook gets 10-15 comments and 100 views.
The growth of the community as mentioned above is also huge, most of the people who were active posters 3 years ago are busy leading communities setting up gyms etc that or they dropped out. The topics of conversation that are important now, how to foster community, how to teach, building up grassroots events and competitions, this stuff that doesn't tend to be very productive to talk about online. Most of the important stuff from the past is in sticky somewhere and veterans are loathe to go over the same old points again for new comers or get dragged into the same tired debates.
Pretty much what Rafe said sums it up. I've been around these forums for almost 4 years now (whoa, it's been that long already?). I'd have to say my first two years were when APK was bustling with tons of activity. I was on these forums for a couple hours a day (WITH OVER 1500 POSTS, NOT EVEN INCLUDING THE 700 OR SO I'VE POSTED IN SOCIALIZE!!11!BWHAHAHA). Now I'm on here for about 10 minutes a week.
So why have I stopped visiting the forums so much? Well, as many have already mentioned, forums change depending on the people who come and go. Rafe said many of us are busy with other things, whether it be leading the community elsewhere, or other things in life have caught our attention. For me, I'm more focused on the local Washington community and my school work. Many others have begun to start their own parkour clubs at colleges or opened up their parkour gyms. We're busy people, we don't have time for browsing a forum all day anymore.
The change in the members also plays a part. I'm going to call the group of people I saw regularly on the forums those few years ago "my generation" of posters. I would see the same people post practically every day, all day long. I got know to the generation of posters that I was apart of pretty well, in fact that's how I've come to know the many traceurs around the states that I do now. When I saw many of them had left to attend to more important matters, I found it less appealing to live, breathe, and eat on the forums. As these friends I came to knew moved on, I felt I should move on too. The discussions change over time (and they run through cycles, actually), and weren't as appealing anymore without the generation of posters I was from. Also, a lot of discussions become repetitive for us that have been on here for a long time. Talking about the difference between PK and FR, or similar ideas a million times is not the most interesting thing do.
As time goes on, people come and go. When people change, discussions change. When discussions change, older members may not find it as appealing. But you see, the next generation of posters (you guys) are disscussing topics as a group, much like my generation did. So everything kinda runs in a cycle. That's how I see it.
6) Encourage well-known practitioners or leaders in the community to post more, even if it's just in a special Advanced section. People, newcomers especially, often come because they saw the moves their heroes did online. If they come on and see Frosti posted just yesterday giving advice or just clowning around, it's a pretty cool feeling.
This. I remember in my first months of learning parkour. I would see the guys from the Tribe or APK Alliance posting on the forum regularly like everyone else. It was really cool. These superhumanbeingpeople were posting and using this forum just like I was. In fact, I was TALKING to them. Through the forums I got to learn about the personalities and backgrounds of each of these guys. When you first start parkour, the guys with big names become your inspiration. But later on, I came to realize that they're just regular people. And I've actually met and jammed with most of these guys. Now they seem like regular, everyday people to me, but will still appear as heroes to new members. It was really cool back then getting to know them in a real, person-to-person conversation on the forums.