Market demand
Market demand is the supply of prospective tenants for each room market. It is different from Room evaluation: demand affects who is available to lease, while evaluation affects how an occupied room performs.
Prospect pools and leasing
Each market has a prospect pool that replenishes over time. Map settings, stars, difficulty, market movement and temporary modifiers can affect it. Permanent tenants search only during daytime. Eligible vacant rooms compete with each other and with outside options; a successful lease consumes one prospect.
Visitors and campaigns
Hotels book on their own schedule. Commercial rooms use visitors, and their demand profiles can increase visitor pull and volume. Advertising and other temporary campaigns can change demand or visitor attraction; disasters can temporarily reduce demand.
Practical play: avoid expecting a large block of identical rooms to fill at once. Improve quality, unlock stars, use campaigns, and build enough visitor attraction and transport.