Social media is changing the way destination branding and tourism marketing organisations work, according to experts who met at the UN World Tourism Organization (UNWTO) & World Travel Market (WTM) Ministers' Summit in London last week.

At the meeting, more than 60 tourism ministers as well as leaders from Facebook, Expedia, Melia Hotels, Eurostar and the World Travel and Tourism Council agreed that the current social media landscape will force destinations to invest further in understanding and engaging travellers through the medium.

The rise of social media has stacked the odds in favour of the consumer.

"Today consumers have access to more information, more choices, and more opportunities to voice their opinions and can be the whistle-blowers for unethical practices or the biggest ambassadors for destinations and service providers," said UNWTO secretary-general Taleb Rifai, opening the summit.

"In this context, branding is an ever-more complex challenge requiring destinations and companies to adjust their structures, their policies and their strategies."

The stakes are high. Rifai referred to the scale of the global tourism market: "There will be 1.18 billion tourists in 2015 – that's four million per day."

One brand that has risen to the challenge is Eurostar. The travel firm has shifted to social media, meaning that there are fewer phone calls being received by its call centre. However Twitter "lights up like a Christmas tree" if there are delays on the service, said Richard Quest, CNN International anchor, who moderated the debate.

It's all hands on deck for the company, with social meaning that customers have more access to support.

"Customers are very savvy. People expect a one-to-one conversation with the company. We have three shifts of people working on Twitter...and we can ask the train manager to see you if you tweet on the train," said Eurostar chief executive Nicolas Petrovic.

However, David Scowsill, president and CEO of the World Travel & Tourism Council (WTTC), warned that destinations must act quickly and communicate truthfully in times of crisis.

While countries market destinations by highlighting the qualities of their people, their nations or particular cultural and natural icons, brands are "at the mercy of so many external forces" over which they have no control, CNN's Quest agreed.

A useful tool is big data. Brands can tap into technology that helps them target the two billion smartphones on the planet, said Facebook's global head of travel Lee McCabe. Facebook and many others can help tourist boards target consumers in this way, he said.

Expedia's global senior vice president Noah Tratt said the firm is working with partners to help it figure out how best to exploit social media and mobile technologies in travel marketing. "We work with tourism partners to test things, to see what works."