moTi - 1:40 pm on Dec 31, 2010 (gmt 0)
Everyone I know and her dog (and the dog's pet and pet's friends too) is on FB.
americans are totally crazy about facebook. i don't exactly know why, maybe it's because americans are rather talkative people or because of the long distances between the residencies of their friends?
anyhow, facebook for sure is the biggest "social network", but it has to be noted that it is not in the least as important in most other parts of the world. for example, the adoption rate in my area and my age group (central europe, 30-40) stays below a third of all internet users with only slight increases. btw, twitter is at one percent..