by Steven Musil
January 4, 2009 10:20 AM PST

Did we turn to Facebook for Christmas cheer, or to cheer up Christmas? The social-networking site, which has been experiencing explosive growth in membership, saw record traffic on Christmas Eve. Facebook achieved its highest-ever traffic level, accounting for 2.18 percent compared with a 1.42 percent average for November, according to numbers gathered by Hitwise.

That's a 54 percent increase compared with the November average and a 53 percent increase year over year. That pattern was mirrored in the U.K., where visits to the social networking site had a market share of 4.65 percent, accounting for one in every 22 Internet visits. So, in this season when faithful friends gather near to us, are we substituting Facebook for face time with our loved ones? Hitwise's Heather Hopkins offers some theories in a blog post on what might have caused the holiday traffic spike.

Facebook's top markets of New York, Chicago, Washington, Boston, and Philadelphia were all hard hit last week by severe weather, which may have prevented many people from getting out and visiting in person, Hopkins notes. Noting that Christmas Day was Facebook's busiest traffic day in 2007 (one day later than 2008), Hopkins suggests that boredom--when coupled with the weather--may have contributed to the increase.

"I received 5 friend requests last week and many holiday wishes," Hopkins writes. "Maybe people were simply bored while stuck home with family and so escaped to computers to catch up with friends." Perhaps the best explanation is that more people were using the site to send their late holiday greetings. Hitwise also saw increases in traffic at Yahoo Mail and e-greetings Web sites, Hopkins said.