For pop-up restaurant events, the real success metric isn't just profit — it's proof of concept + future demand. When we helped promote a speaker-chef crossover event at Gotham Artists, we tracked three key things: 1. Repeat intention rate - after the event, we sent a quick one-question text: "Would you attend something like this again?" If over 70% said yes, we knew we had a viable experience. 2. Email capture vs. walk-ins - we weren't just selling tickets, we were building a list. If at least half of attendees opted in for future events, that meant we weren't just getting eaters — we were getting fans. 3. Cost-per-conversion on local ads - we tested low-budget geo-targeted ads and measured how many people actually converted (RSVP'd or purchased). If the cost stayed under a set threshold (e.g., $12 per sale), we considered it scalable. Of course, we tracked revenue — but it was just one piece. For pop-ups, the real win is momentum: if you can walk away with proof people want more, you're not just running an event — you're building a brand.