TanaCon sold 20,000 tickets to a venue built for 5,000

In June 2018, YouTuber Tana Mongeau — who had 3.5 million subscribers — announced TanaCon, a free meet-and-greet at a Marriott hotel in Anaheim, held the same weekend as VidCon. She said VidCon had sidelined her; the event was positioned as a creator-led alternative.

Mongeau and her organiser, a company called Good Times, expected around 5,000 attendees. Roughly 20,000 showed up. The venue had no capacity for the crowd: thousands were left outside in the heat, an angry mob rushed the lobby, and the event was shut down the same day.

Attendees described being stranded without water, information or the promised meet-and-greets. Refunds were eventually issued for paid VIP packages, but some fans pursued legal action. Media coverage universally compared TanaCon to Fyre Festival — the comparison a brand activation never survives.

They forecast attendance from follower counts, not ticketing data, so no crowd plan existed; the 4x turnout shut the event in one day.

The organiser estimated attendance from social-media follower counts, not from ticketing data or venue capacity — a 4x error.

No crowd-management plan, security staffing or contingency existed for a turnout larger than the estimate.

The event was announced as a response to a personal grievance with VidCon, so the planning timeline was driven by the competitor's schedule, not by readiness.

Follower counts are not attendance forecasts. A free event with no ticketing has no capacity limit and no crowd data until the crowd arrives.