Chicago – Thanksgiving Day openings at brick-and-mortar stores contributed to an 8.2 percent spike in foot traffic over the Thanksgiving weekend, to more than 594 million store visits.

But according market research firm ShopperTrak, retail sales trailed traffic, edging up 2.7 percent year over year to about $22 billion for the four-day selling period.

Sales were slightly down on Black Friday, observed ShopperTrak founder Bill Martin, as shopping was pulled forward by Thanksgiving Day promotions.

“Shoppers follow value, and this year, for the first time, retailers presented significant value for shopping on Thanksgiving Day,” Martin said.

That, and the extension of Black Friday into a weeklong event, may be diminishing the importance of a single shopping day, he noted.

Separately, Best Buy told the local Minneapolis StarTribune that Black Friday sales of mobile phones, laptops and e-readers exceeded its full-day hardware projections by 3 p.m. Central Time, and that BestBuy.com “broke records” on Thanksgiving and Black Friday.