Garage-Sale Playbook – First-Principles Edition  
(Applies anywhere, tuned for Lewisville, Texas)

1. Objective  
   Maximize net profit (sale receipts – all costs – opportunity cost) while staying within legal and social constraints.

2. Universal Constraints  
   A. Legal: city ordinances, permit limits, property-line rules, signage rules.  
   B. Social: neighbor tolerance, safety, customer trust.  
   C. Physical: driveway size, daylight hours, weather.

3. Core Levers (first principles)  
   · Traffic Volume (# of qualified buyers who see your goods)  
   · Conversion Rate (% of viewers who purchase)  
   · Average Transaction Value ($ per buyer)  
   · Operational Cost (time, money, risk)  

4. Mapping Lewisville Rules to Levers  
   Rule → Lever Effect  
   - Free two-per-year permit → caps Traffic Volume (max 2 events)  
   - Must be on private property → constrains Traffic Volume (no street spill-over)  
   - Online permit by Friday 10 a.m. → adds Operational Cost (deadline risk)  
   - Signage only on your lawn → caps Traffic Volume; mitigate with digital ads

5. Optimal Tactics (derived from levers)  
   Traffic:  
   • Schedule on high-footfall weekends (weather app + local events calendar).  
   • Post to zero-cost digital channels (FB Marketplace, Nextdoor) the moment permit is approved.  
   Conversion:  
   • Price anchoring: big bold “$1 table” draws eyeballs → higher walk-up rate.  
   • Power strip on site → buyers test electronics instantly → removes friction.  
   Transaction Size:  
   • Bundle pricing (“3 books for $5”) pushes unit economics up without extra traffic.  
   Operational Cost:  
   • Use existing tables/chairs, borrow folding racks → cash layout near zero.  
   • End-of-day donation run to Goodwill → converts unsold inventory into tax deduction instead of storage cost.

6. Day-of Execution Checklist (minimum viable)  
   07:30  Permit printed & taped to front window (legal compliance).  
   08:00  Two signs max on lawn facing both traffic flows (traffic).  
   08:15  Cash apron on + $100 in small bills (operational).  
   08:30  QR code taped to table linking to digital price list (conversion).  
   14:00  “Half-price last hour” call-out (transaction size).  
   14:30  Signs in, lawn swept, leftovers in car for donation (social constraint satisfied).

7. Post-Mortem Template  
   Net profit = Gross – (permit $0 + ad spend $0 + time 8 h × self-wage $15) – unsold write-off $0 (donated).  
   If profit ≥ target, replicate. If not, adjust Traffic (better ad copy), Conversion (pricing), or Transaction Size (more bundles).

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