More than a third of new marriages begin with an online meeting, and partners who met online tend to have higher marriage satisfaction than those who met offline, according to a study published Monday.

A nationally-representative sample of more than 19,000 people who married between 2005 and 2012 found approximately 35 percent of all new marriages began with an online meeting, with about half of those people meeting their spouse through dating sites such as eHarmony and Match.com. About 20 percent of online meetings happened through a social networking site such as Facebook or Twitter, and about 15 percent of those meetings happened through instant messaging, email or a chat room.

Offline meetings were still the most likely place for spouses to meet, with the largest percentage of spouses meeting through work (21 percent), mutual friends (19 percent) or school (10 percent). Less likely meetings included a place of worship (4 percent of offline meetings), a bar (9 percent of offline meetings) and blind dates (2.5 percent of offline meetings). Less popular online meeting places included multiplayer game sites (3.5 percent) and "virtual worlds" (2 percent).

Researchers from the University of Chicago found a small but noticeable difference between relationships that started online versus those that started offline. People who met online were slightly less likely to be divorced than those who met offline, and those who met online scored higher on a marriage satisfaction survey than people who met offline.

"These data suggest that the Internet may be altering the dynamics and outcomes of marriage itself," John Cacioppo the study's lead author, said in a statement.

The study was commissioned and paid for by eHarmony.com, one of the world's most popular dating sites, but was published in Proceedings of the National Academy of Sciences, a journal known for peer-reviewed research. The study was corroborated and reviewed by researchers at Harvard University.

People who met online were most likely to be between the ages of 30 and 39 at the time of the survey (conducted in June 2012). Spouses who met online were also more likely to be employed and had higher incomes than those whose marriages began offline.

Cacioppo has several theories for why online marriages tend to be more successful: Previous studies have found people who meet on sites such as eHarmony are more likely to be actively looking for a life partner, whereas people who meet offline might feel rushed into a marriage. He also says online sites have "a larger pool of potential spouses" so people can "be more selective in identifying a compatible partner."

Although the researchers found that marriages that had started online were more likely to remain intact, there was just a 1.6 percentage point difference between the divorce rates of the two groups (6 percent for those who met online, 7.6 percent for those who met offline).

"Marital outcomes are influenced by a variety of factors," he writes. "Where one meets their spouse is only one contributory factor, and the effects of where one meets their spouse are understandably quite small and do not hold for everyone."