Why it worked
The video provides high-utility, shareable information (dates) to build trust, then pivots to a specific, time-sensitive, and low-cost travel offer that feels like a natural extension of the content.
Product placement
HolidayPirates (the creator) appears as a watermark/handle; it is the travel deal service being promoted. Removing it would change the source of the deal, but the deal itself is the product. York Christmas market stay (the specific travel deal) is the product being sold; it is the destination of the CTA.