If you want to fundraise from online communities, don’t start by asking for money. Start by developing a community of people that care about the issue and are actively engaged on the issue, then ask for money.
You begin by reaching out to people that care. Add them to a mailing list or ask them to join a Facebook group about the issue. Focus on building connections between them. Ask their advice on topics, give them small projects they can do that help (e.g. writing to local newspapers, helping develop proposals, feedback on your new website etc).
Begin interviewing them about their support. Offer online polls and ask them what skills they have that you might be able to use. You might find some great designers, lawyers, accountants and marketers willing to volunteer their time.
You want every member to be as engaged and involved as they can possibly be within a tight-knit community.
Then, finally, you set an achievable milestone. It might be $2000, it might be $20,000. You state clearly why this amount of money is needed. You encourage every member to do what they can to raise that money and celebrate the small actions members do to help.
Creating a community to raise money takes longer. However, in doing so you’re cultivating an invaluable asset of engaged people who want to help you.