People may complain that marketing for the winter holidays is starting earlier every year, but retailers may just be following consumer buying habits, according to findings from multiple studies.

A survey from RetailMeNot and Kelton Global found that 54% of shoppers plan to start their holiday shopping before Black Friday, which is the Friday after Thanksgiving, or Cyber Monday, the Monday after Thanksgiving. In fact, 45% of consumers will start before November and 25% before October.

Retailers are already jumping on the trend, with an early email marketing and sales. For example, Groupon Goods sent out the an email with the subject line “Cyber Monday Sneak Peek” and offering sales on mattresses, perfume, electronics and other goods.

Millennials, consumers from ages 22 to 37, are driving the trend toward earlier shopping, with a quarter of all millennials shopping year-round, according to another study from Yes Lifecycle Marketing. In total, 58% of that generation plan to start shopping prior to Thanksgiving.

However, the study found that Black Friday is still important, with 37% of consumers planning to make at least one purchase on the traditional shopping kickoff, which falls on Nov. 24 this year, and 34% expecting to make a purchase on Cyber Monday, which is Nov. 27 this year. In October, Salesforce predicted that online purchases on Black Friday would surpass Cyber Monday online purchases this year.

“Black Friday and Cyber Monday still hold an important role for marketers and retailers,” says Michael Fisher, Yes Lifecycle Management’s president. “However, marketers shouldn’t focus on these shopping holidays alone. Accounting for consumer expectations and the shopping habits shaped by their generation can enable brands to create a truly unique and personalized holiday shopping experience.”

However, a Market Track study suggests retailers may be wise to invest in online marketing for the holiday kickoff. Just 30% of respondents to their survey said they would shop in stores on Thanksgiving Day (Nov. 23) and only 40% would brave the Black Friday onslaught.

Instead, shoppers plan to start their holiday shopping online, with 40% of Market Track respondents planning to buy online on Thanksgiving and 54% expecting to make an online purchase on Black Friday.

The study also found that 41% of shoppers plan to plan to do the bulk of their shopping between the Thanksgiving Day and the end of Cyber Monday, making the holiday weekend vital for many retailers’ holiday plans.

“The decline in both store traffic and positive consumer sentiment towards Black Friday in-store events is well-documented. The reality is the battlefront has shifted to digital commerce, and that trend is only going to pick up steam,” said Ryne Misso, director of marketing at Market Track.