Social media is impacting the way we give gifts, according to a new study by researchers from Cornell University, MIT and Facebook.

The researchers found that the spread of online gift-giving in social networks is causing people to give more gifts both online and in person.

“The exchange of gifts is an age-old human behavior and it has been co-evolving with technological trends,” said René Kizilcec, assistant professor of information science at Cornell University and lead author of the study. “Online gift-giving has social implications insofar as it appears to increase the overall amount of gifts exchanged, which can contribute to strengthening existing social relationships.”

The study will be published in the Proceedings of the SIGCHI Conference on Human Factors in Computing Systems later this month.

The researchers analyzed digital traces of 1.5 million online gift exchanges between U.S. adults on Facebook, which enables users to give gifts instantaneously and over long distances, in 2013.

Complementing this data with additional surveys, the researchers found that about half of these gifts were unlikely to occur in person or through other online channels.

During the study, Facebook sent users notifications of their friends’ birthdays and offered the option of sending online gifts, such as gift certificates to online retailers like Amazon or chains like Starbucks.

The researchers found that online gifting through the platform both complements and substitutes for offline gifting. While 58 percent of gift-givers said they still would have given a gift in person, 42 percent said it would have been more difficult to do so.

“It initially appeared as if online gifting was spreading on Facebook by paying forward acts of kindness,” Kizilcec said in a statement. “Upon closer inspection, it became clear that there is a broader network of gift exchanges, and these acts of reciprocity seamlessly transcend the online and offline world.”

The study revealed that online gift-giving is often reciprocal, meaning that Facebook users who had received gifts were often compelled to give one in return. Surveys showed that three-fourths of online gift-givers had previously received a gift from the person to whom they sent an online gift.

“We found substantial evidence of social influence driving gift-giving behavior,” Kizilcec said in a statement. “This boost in online gifts was not just the result of substitution away from offline gifts; but rather, it appears that receiving online gifts inspires people to give more gifts overall.”

The researchers found that online gift-giving was more socially acceptable to those who observed friends’ participation rather than learning about it via non-social encouragement.

Recipients of gifts through Facebook were found to be 56 percent more likely to also give an online gift. Accordingly, approximately a third of online gifts through Facebook were inspired by receiving a gift in the past.

The study also found that age influenced online gift-giving tendencies. Facebook users between the ages of 45 and 64 most commonly gave gifts through the platform, while millennials were less likely to do so. The researchers attribute this to older users giving gifts to people in their generation and in younger generations.

However, millennials were twice as likely as non-millennials to give online gifts after receiving one. This suggests that they are easily influenced into using the platform to give gifts, Kizilcec said in a statement.

As Facebook and other social media platforms have continued to grow globally, online gift-giving may also have significant social, cultural, and even economic implications. “By lowering the barrier to give gifts, online gift-giving may also facilitate the development of new relationships,” said Kizilcec. “The culture around gift-giving has evolved as online gifts and gift cards have become widely adopted and socially accepted. Finally, as more gifts are being purchased online and the overall amount of gift giving rises, online gift-giving further increases the market size of gift purchasing.”