The founders share the 12 key practices they used to reach over 1,000 paying customers in 20 weeks—from locking in 90% weekly retention before marketing to weekly product shipping and firing misfit clients early. Each rule focuses on validating fast, staying small, tracking burn rate, and leaning on real user feedback.

• No acquisition spending until weekly retention hit 90%, over the first 20 weeks
• Put a credit-card paywall on day two to test real willingness to pay before building further
• Kept headcount at two founders while shipping code every Friday and tracking burn rate/runway weekly to stay "default alive"
• Fired misfit customers early, prioritizing ten super-fans over a thousand lukewarm users, en route to 1,000 paying customers