The storyHow they got there
Wilson Bright and Marc Roca launched Senja in 2021 with a monthly operating cost of $35. The product collected and displayed customer testimonials — genuinely useful for SaaS founders and creators who needed social proof without engineering work.
The first ten customers came from Wilson posting in Indie Hackers, Twitter, and small Slack communities. The first hundred came from the product itself: "Powered by Senja" badges on every embedded testimonial widget turned each customer's testimonial wall into a free billboard. The viral surface was built into the product on day one.
At maturity, the channel mix: Twitter/X build-in-public and founder networks (~35%), SEO on "testimonial software" comparison pages and alternatives to competitors (~25%), word-of-mouth among solopreneurs and coaches (~25%), Product Hunt multiple launches (~10%), and affiliates (~5%). Cold outreach was killed — low conversion for this B2C-leaning tool. Twitter and SEO were doubled down on.
Unit economics: CAC around $20–40, ARPU around $25–40/month, LTV around $500–800, and free-to-paid conversion around 4–6%. Six months of daily build-in-public posts with zero revenue taught the team that audience quality matters more than audience size — the small percentage who were ideal customers converted at high rates and became advocates. By 2024, $50K+ MRR with 20,000+ users.
Channel MixWhere the growth actually came from
Most case studies hand-wave channels. Here's the rough allocation — not in dollars spent, but in users acquired — across the routes that actually mattered.