Bootstrapped growth is slower but more sustainable. Channels: content marketing, SEO, social presence, community, referrals. Pick one or two and go deep.
Content works: blog posts, docs, tutorials drive organic long-term. SEO builds compounding traffic—the earlier you start, the more you benefit. Build in public—Twitter, newsletters build audience.
Paid acquisition works at scale but is expensive until you optimize. Start with channel exploration: what's cheapest for your audience? Track CAC and LTV carefully.