Despite an upturn in sales over the long weekend, year-to-date online spending has declined by four percent to $10.4 billion, comScore reported Monday.

The decline comes despite a one percent increase in online sales on Black Friday, the day after Thanksgiving and the official start of the holiday shopping season, the Virginia-based Internet marketing research firm said. Online sales on Friday reached $534 million, the report said. Combined with spending on Thanksgiving Day, online sales were up by two percent compared to the same period last year.

Retailers are waiting to gauge the impact of Cyber Monday, the first workday after the holiday weekend when many consumers continue shopping online. In the past few years, online spending growth rates for the first Monday after Thanksgiving have been on par with final holiday season growth rates, said comScore Chairman Gian Fulgoni.

“Cyber Monday may well prove to be an important indicator of whether the decline in spending that we’ve seen during the first few weeks of the online holiday season will continue for the balance of the year,” Fulgoni said in a statement.

Nearly 85 million consumers are expected to shop online on Monday, up by 17.5 percent from last year, according to

Fulgoni said Black Friday shoppers responded positively to aggressive promotions and discounts offered by stores, and should be equally attracted to similar deals online.