Australia's tourism industry on Sunday has been told to jump on board the new social networking rage, or risk losing business and being left behind, local media reported.
Foursquare is a social networking tool that allows users to track the location of their friends through the Global Positioning System (GPS), and share information and reviews about businesses and attractions in their areas.
It is also a game, with players picking up badges and the title of mayor by visiting cafes, restaurants or hotels and tourist attractions that give them the chance to reward repeat customers with discounts or gifts.
And now it is about to have a huge impact on the tourism sector, and indeed on all businesses, social media commentator Laurel Papworth said.
"Foursquare is word of mouth in its purest form," Papworth told the Australian Associated Press.
"When you click on, you write a review or make a statement, ' The service is great here', or 'Great coffee - terrible cakes'.
"And remember, this is all mobile: you're not in front of your computer, you're on your mobile phone and your comments can be linked automatically and published instantly on Facebook and Twitter.