Expedia and the Netherlands Board of Tourism and Conventions (NBTC) are looking to Twitter to help promote the country's many attractions to British, French, and German travelers and in turn boost social engagement among that demographic. As part of the campaign, dubbed #VanGogh2015, for the next six weeks Expedia's Twitter accounts in each of those countries will feature six of Vincent Van Gogh's masterpieces, commemorating the 125th anniversary of the painter's death. Tweets from the brand will direct users to a landing page where the travel site is utilizing Twitter's Flock to Unlock feature, in which users can unlock exclusive content by retweeting. Each retweet represents a brushstroke; with each one, the image becomes clearer. After a predetermined number of retweets - it will vary, depending on the year of each painting's completion - a painting is revealed and all retweeters will be entered to win a trip for two to the Netherlands. Get the full story at ClickZ