"An increasing number of companies are 'listening in' to customers' public conversations on social media"

CNBC:

With the use of a technology called geo-fencing, they can see every public posting on a social-media platform done from within their properties.

For example, Karin Timpone, Marriott's chief global marketing officer, said if someone posts a wedding engagement photo from one of its properties, the M Live team will reach out and contact the front desk to let them know. The hotel will often then reach out to the customers and give them champagne, a room upgrade, a free appetizer — something to show that Marriott values them.

...

Recently, a man posted on Twitter announcing that he was the first person to catch all of the Pokemons. Marriott reached out to him and is now sponsoring him and provides him free lodging around the world.