Hi Jennifer, in my career spanning almost 20 years, I've seen several causes of community failure. I'll list out a few and open up the thread for others to contribute.
Too Much Initial Hype, No Follow-Through
Most of the communities launch with a lot of initial hype. Community managers announce the new community on various platforms, social media, newsletters and expect the members to join.
Unfortunately, this never works.
Founder Burnout
The community founder burnout is real. In the initial days of community building, the founder has to create content, advertise, talk to members, take care of the tech-stack; which is pretty exhausting. A lot of communities die because of founder burnout.
Platform Dependency
This one is based on personal experience. When communities change platform and do not plan it well (redirects, member alignment, content) communities die a slow death. One of the communities I was a part of switched the platform and didn't implement proper redirects.
Result? The traffic died and members didn't like the new platform.
Not Defining The Purpose of Community
This one is classic. Most community builders rush into the process of community building without knowing 'why' their community should exist. Without a purpose, you cannot plan your community growth.
Poor onboarding flow
A community needs to welcome its new users. A poor onboarding flow is often the reason most new users never become active.
No Community Manager
A community doesn't grow on its own. You need a community manager to nurture relationships, moderate the community and create content relevant to the community.
Over-enthusiasm about Vanity Metrics
I've seen a lot of community managers focus on 'registration count'. Simply getting new members while ignoring content and existing members is a leading cause of community death.
Vanity metrics are good for marketing department. However, a community needs to focus on the real engagement metrics that help community grow and help its members.
Toxic Culture
Toxic culture is a leading cause of communities losing momentum over time. When the moderators and community managers do not control the toxic behavior in the community, it leads to community members leave the community silently.
No Personal Connections / Bond
A community thrives when members develop personal connection with each other. Communities that ignore this aspect of community building eventually die.
Niche: Too Broad or Too Narrow
In the early days of community building, I used to think that a broader community has a better chance of winning because it offers everything for everyone.
I was totally wrong.
The key is to build an active niche community and then grow from there. When starting a community, it's important to find a niche that has potential to grow.
What's the solution?
The key to building a thriving community is to plan its growth on day #1. If anyone is looking to start a new community, follow our 30-60-90 Guide to Community Building. It shares a detailed, step-by-step plan to building a community in 90 days.
I hope this helps. I request fellow community members to share their views.