The document discusses how personalization can increase ancillary revenues for travel companies. It explains that personalization begins with understanding individual customers using information from various sources like past purchases and interactions. This enables companies to send tailored, timely communications about additional products and services. Studies show personalized outreach can significantly increase customer responsiveness, purchase rates, and opening rates compared to generic communications. The key is building a profile for each customer and curating personalized recommendations and offers for additional travel products and experiences.