This Bud’s for you…and it’s free. In an attempt to stem a U.S.-sales slide, Budweiser, the most popular brand of beer in America, is unleashing a massive promotional campaign, starting with a nationwide giveaway of 500,000 free samples in bars and restaurants across the United States. Owned by the Belgian multinational Anheuser-Busch Inbev, Budweiser is struggling to attract younger drinkers who prefer comparatively healthy, low-calorie beers or craft brews. The brand experienced its biggest drop ever last year, with sales down 9.5 percent, according to Beer Marketer’s Insights. Budweiser’s response is a “Budweiser National Happy Hour” this Wednesday, and the company is planning to give away half a million beers by mid-October.