175 million people is far more than the number of people who voted in the 2008 US presidential election (131,257,328). It’s far more than the population of Mexico (111,211,789). It is far larger than the nation with the second largest national economy on Earth, Japan(127,530,000). And it’s still growing like crazy. Facebook, of course, is not really comparable to a country, but at some point the size of a community becomes a very important feature.