With national retail sales expected to increase only slightly throughout the entire holiday season, just 10 days will make or break the period for retailers, according to ShopperTrak —a provider of retail foot traffic counting, managed services and business analytics.

“Since Christmas falls on different calendar days each year, the shift impacts which days are the busiest. Some change in ranking or drop off completely,” says ShopperTrak co-founder Bill Martin. “Retailers can’t assume historical patterns will completely repeat themselves, and only by tracking in-store traffic can they understand the trends and prepare to capture business this holiday season.”

According to ShopperTrak, the week before Christmas will be especially important this year, as five of the top sales and foot traffic days will occur between Dec. 18 and Dec. 24.

While Black Friday is typically the strongest shopping day of the season, one third of all holiday sales are historically made in the week prior to Christmas. Retailers can expect consumers walking into their stores that week have conducted plenty of online research and are ready to buy.

Historically Strong Shopping Days

Prior to Christmas, ShopperTrak expects Black Friday (Friday, Nov. 25) to remain the top performing sales and foot-traffic day for the eighth year in a row, followed by Super Saturday on Dec. 17.  Last year, Black Friday showed an increase in both sales and foot traffic over 2009; foot traffic increased 2.2 percent and sales increased 0.3, representing $10.69 billion in consumer spending and the largest dollar amount ever spent on the day.

Black Saturday, the day after Black Friday, historically shows a decline in sales from the previous day, but remains one of the season’s top performers. Black Saturday 2010 showed a 0.9 sales decrease from the previous year, representing $6.06 billion dollars spent. This year, ShopperTrak expects Black Saturday to rank sixth in both sales and foot-traffic.

“Annually Black Friday weekend’s strong start is one bookend to the season and the week leading into Christmas is the other,” added Martin. “Successful retailers will prepare for these critical top ten days, track their traffic internally and make adjustments to capitalize on shopper opportunities walking through their doors.”

Last year’s top 10 busiest GAFO Retail Sales days accounted for 28% of GAFO Retail Sales for the Nov. and Dec. holiday season, and ShopperTrak expects this year’s top 10 to be just as important.

The following table shows ShopperTrak’s forecasted busiest holiday sales and traffic days: