You should participate in a community to gain influence.
Influence isn't your direct authority. Influence is your ability to make things happen. When you ask members to take action, they take the action. That's a valuable skill to acquire.
There are four broad pathways to influence summarised below:
You can avoid criticism and complaints. Use positive language. Inject energy and happiness into discussions. Frequently contact members to get the latest updates on their news. Be the person that initiates fun activities, brings in the in-jokes, makes members glad to be around you.
Path 2) Create reciprocity cycles.
If you help people, they'll help you in the future. Contact your members and identify their challenges. Send through news items, make introductions, and offer frequent support and advice to help them. Don't ask for anything in return. Build up as many of these cycles as you have the time.
Path 3) Be the expert (or the most talented).
Participate less, but make every contribution a valuable one. Add unique expertise or perspectives to every post. Summarise the latest trends or discussions from the top experts. Read the latest books on the topic. Go beyond the cutting edge of what members are doing and report back.
Path 4) Leverage connections.
The better your social capital, the more influence you have. This comes in two forms. Strong relationships with key members in your sector. Weaker relationships with as many community members as possible. You can build strong relationships by playing to the influencers' egos. Interview them, invite them to host a webinar for your audience, flatter them. You can build weaker connections by being an active host of regular events/activities. Everyone knows who you are. You can travel and arrange as many coffee meetings with members as possible.
You might be thinking, can't I do all 4? Only if you want to do all 4 badly.
Those that try to take on more than one usually do none of them well. To gain influence you have to pick one of these paths and focus solely upon it. Likability is most common but least reliable. Reciprocity is most reliable but the most effort (and takes the longest). Expertise is the most difficult and competitive. Leveraging connections may be the easiest but least effective.