Dive Brief:

• A study of 120 shoppers who said they intended to buy electronics merchandise did most of their eventual planning and purchasing online, even though some of the same group had said previously their spending would be split between online and offline, according to a press release from market intelligence firm GfK.

• About 82% of the "intenders" visited a retailer site or app during the study period of Nov. 1 through Nov. 27, while 44% went to an electronics brand site, GfK said. By contrast, only half (52%) of these shoppers said they conducted research or made an electronics purchase in a physical store.

• The online vs. offline split was even more pronounced among shoppers who actually made purchases, with about 74% buying their electronics products online, and 26% buying offline. Of the online purchases, 44% occurred via mobile devices and another 46% via laptop.

Dive Insight:

Prior to Black Friday, a GfK survey of those intending to make consumer electronics purchases found that shoppers expected to spend an average of 49% of their holiday spending budgets in physical stores, and the other 51% online. That's not how things turned out.

GfK's study combined pre- and post-shopping surveys with extensive behavioral data, including tracking of mobile activities, for the same 120 consumers. This research showed that ultimately the spending split did not follow the 51% online to 49% offline expectation. Rather, 64% of spending happened online, to only 36% at brick-and-mortar. Of the online spend, 24% occurred on mobile devices.

The heavy shopping activity via mobile should come as no surprise at this point, and neither should the tendencies of the different demographics. For example, millennials between the ages of 18 and 37 spent 30% of their electronics budgets via smartphones or tablets, while the percentage was half that for Baby Boomers between the ages of 53 and 70.

During the 27-day period, consumers averaged 2.6 shopping sessions daily on their smartphones, with the most frequent activity occurring on Thanksgiving Day, at 3.8 sessions per shopper. Meanwhile, Cyber Monday saw longer shopping sessions, as time spent using retailer sites or apps was about 17.2 minutes per electronics shopper vs. an average of 12.1 minutes across the studied period.

Overall, shoppers came out earlier than expected, meaning retailer marketers need to show up early for the holidays, too, but shouldn't let up once Cyber Monday arrives. "[R]etailers need to communicate early and often during this crucial season," Wendy Wallner, GfK's EVP for the retail industry, said in a press release. "Retailers should use the week through Thanksgiving to facilitate digital research with easy comparisons, reviews, promotions, and matching the right product based on [future] needs… When it comes to promotions and other ways to direct resources, Black Friday and Cyber Monday are both critical."

This story is part of our ongoing coverage of the 2017 holiday shopping season. You can browse our holiday page and sign up for our holiday newsletter for more stories