BY DAN BERTHIAUMEChicago Customers at malls are actively posting via social media, but leaving out information that could help mall-based retailers. According to a new study from location-based social media monitoring firm Geofeedia, 91% of mall-based social posts lack relevant hashtags and/or keywords, and 8% of posts only contain photos or videos.About 5% of posts from roughly 13,000 unique users and 16,500 unique visits to four major U.S. malls Roosevelt Field, New York, Beverly Center, Los Angeles, Northpark Center, Dallas and Water Tower Place, Chicago were made from the parking lot. Leading keywords in these posts were dinner, love, and happy.The most social day of the week for mall shoppers was Saturday and the least social day was Friday, while the most social time of day was 5 p.m. Other findings included that Chicago shoppers made the most posts per store (36.6), Dallas shoppers had the most relevant hashtags and keywords (16% of all posts contained at least one), and New York City had the most social parking lot (36.6 posts per shopper).