The holiday shopping season kicked off early, as several retailers began offering deals on Thanksgiving Day. Many people complained about the early start and the mad rush for deals — but they went out shopping anyway. About 15,000 were in line for Macy’s opening in New York, the retailer’s CEO said in an interview.

The day after Thanksgiving, called Black Friday, is typically the biggest shopping day of the year. For a decade, it had been considered the official start of the holiday buying season. But in the past few years, retailers have pushed opening times into Thanksgiving night. They’ve also pushed up discounting that used to be reserved for Black Friday into early November, which has led retail experts to question whether the Thanksgiving openings will steal some of Black Friday’s thunder.

The holiday openings came despite threatened protests from workers’ rights groups, which are opposed to employees working on the holiday instead of spending the day with family.

Overall, the National Retail Federation expects retail sales to be up 4 percent to $602 billion during the last two months of the year. That’s higher than last year’s 3.5 percent growth, but below the 6 percent pace seen before the recession.

Analysts expect sales to be generated at the expense of profits, as retailers will likely have to do more discounting to get people into stores.