As one of the most important seasons on the retail calendar approaches, retailers can expect bitter news to accompany the sweet: back-to-school shoppers will spend more than last year, but make fewer trips to the store.

According to ShopperTrak — the world's largest counter and analyzer of retail foot traffic — national retail sales, when compared to the same period last year, will rise 3.8 percent in August, while foot traffic will decrease 2.9 percent.

ShopperTrak measures foot-traffic in more than 25,000 stores inthe United Statesand analyzes the data in a proprietary econometric model to create its National Retail Sales Estimate™ (NRSE) of general merchandise, apparel and accessories, furniture and other sales (GAFO). Its estimate precedes the federal government's official reports by several weeks and sinceJanuary 2005it has been accurate to plus or minus 3 percent.

U.S. retail spending has been positive sinceFebruary 2010, and ShopperTrak's back-to-school sales increase prediction follows 17 consecutive months of year-over-year growth, according to previous ShopperTrak NRSE reports. Because gas prices are 30 percent higher this summer than last, however, ShopperTrak expects foot-traffic to drop by 2.9 percent. In 2010, the back-to-school season saw a 0.5 percent decline in foot-traffic compared to 2009. The forecasted numbers may drop further if Congress fails to act on the U.S. debt ceiling and nervous Americans decide to cut their spending.

"With back-to-school shoppers planning fewer trips to the store — and continued economic uncertainty — retailers must maximize the limited number of opportunities to convert browsers to buyers," said ShopperTrak co-founder,Bill Martin. "Tracking daily foot traffic and understanding store traffic patterns will equip retailers with meaningful business intelligence to ensure the best possible in-store experience for the customer and the maximum shopper conversion rate for the store."

Back-to-school sales and traffic have historically served as a key indicator for the winter holiday shopping season for retailers. The data also help investment firms estimate future sales and earnings of publicly traded retailers. Retailers who track and benchmark their store traffic and sales are in the best position to accurately pinpoint trends, popular products and take the necessary steps to improve store performance.