By CANDICE CHOI and CHRISTINA REXRODENEW YORK (AP) â¿¿ Facebook isn't just for goofy pictures and silly chatter. Whether shoppers know it or not, their actions online help dictate what's in stores during this holiday season. After polling customers on the social media site, Macy's decided to carry denim jeans in bright neon hues rather than pastels. Wal-Mart for the first time decided to let customers vote on which toys they want discounted. And to better plan orders for the decorative flags she sells, a small business owner in Mississippi is running a contest that encourages customers to chime in about how they're decorating their homes this winter. The impact of social media on a company's bottom line is tough to quantify, with no hard data on how millions of Facebook fans and Twitter followers translate into sales for stores. But during the holiday shopping season, a roughly two-month period when retailers can make up to 40 percent of their annual revenue, stores are uncovering a valuable use for all the seemingly useless online muttering: market research. The result is that whenever folks press the "like" button to give their seal of approval for a particular company's page or make a comment on how much they like the leather boots they just bought, they're helping everyone from independently-owned small shops to the nation's biggest retailers make decisions about what products to stock up on, what to play up on the sales floor and what promotions to offer online. For the first time this year, one of Macy's Inc.'s apparel buyers suggested the company solicit feedback on Facebook on which colors it should stock for "Else" brand jeans in the fall ahead of the holiday shopping season. Several weeks later, with about 2,500 "likes" and 750 comments, "Very Vivid" colors in bright blue, orange and red were declared the victor over softer shades such as baby pink and baby blue.