In A Marketer's Guide to Reaching the Generations, Yes Lifecycle Marketing surveyed over 1,000 consumers of all ages and found that 60 percent of all consumers begin holiday shopping before Black Friday. From these, millennials are most likely to plan ahead, with 58 percent reporting they start shopping prior to Black Friday. In contrast, more than a third of centennials said they start their shopping after Black Friday and just over 15 percent admitted to waiting until after Dec. 15.

The popularity of many shopping holidays varied across generations, but 37 percent of all consumers made a purchase on Black Friday and 34 percent did so on Cyber Monday. When broken down by generation, only 21 percent of baby boomers made a purchase on Black Friday -- compared to 54 percent of millennials. Despite this, millennials are the more likely generation to shop year-round with the majority (60 percent) beginning their holiday shopping before Black Friday.

"Black Friday and Cyber Monday still hold an important role for marketers and retailers. Consumers expect that marketers will incorporate these holidays into their messaging and brands will ultimately miss out on revenue opportunities if they don't include them in their strategy," said Michael Fisher, president of Yes Lifecycle Marketing. "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."

Across generations, consumers say they refer to apps, desktop websites, mobile websites and physical locations more frequently during the holidays and 40 percent of all consumers say they visit a brand's e-commerce website more often during the holidays.

However, channel preferences for holiday shopping can vary significantly by age. The report found that, when compared to other generations, 45 percent of centennials shop in-store during the holidays, more than any other generation. Centennials are also most likely to find social media influential during the holidays, with 26 percent admitting to the influence of social on their purchasing decisions. This indicates that younger shoppers still heavily value the in-store experience, but want a robust cross-channel shopping experience.

The report also shows that the majority of millennials and centennials are influenced by content, at 90 percent and 87 percent, respectively. In contrast, one in three baby boomers (32 percent) said content does not influence their holiday purchase decisions, demonstrating the gap in generational consumer preferences.

"What resonates with millennials and centennials in holiday retail marketing isn't necessarily going to speak to Gen X and baby boomers," said Michael Iaccarino, CEO and chairman of Infogroup, parent company of Yes Lifecycle Marketing. "Marketers need to rely on accurate data and flexible technology to effectively cater to the needs of consumers across age groups and drive more engagement and conversions."

Additional findings from the report include:

• Despite claiming that they're not price sensitive, centennials and millennials are more than twice as likely to make Black Friday purchases than baby boomers.

• Twenty-nine percent of baby boomers use the same shopping channels year-round and don't deviate for the holidays, compared to 13 percent of centennials and 14 percent of millennials.

• Centennials are twice as likely as Gen Xers to refer to mobile sites during the holidays.

• Only 13 percent of baby boomers refer to mobile sites during the holidays.