The opportunities to leverage niche communities for growth are vast. Increasing dissatisfaction with big social networks drives people to smaller communities. That trend should be on every Growth Hacker's radar. When going after an established community, do not try to aggressively exploit it. Instead, become part of it, show people the value of your product and raise brand advocates. Authenticity goes a long way. Workarounds for "passive Piggybacking" are the acquisition of the community or advertising on it. 70% of communities are destined to fail. [*] The biggest community killers are outdated content, low engagement and missing pathways to build relationships with other members.One health indicator is the amount of comments per thread. If it's slowing down over time the community might be at the end of its life-cycle. So, before picking a community for growth, make sure it's alive and thriving.