Note on this list the stubborn persistence of Yahoo’s Geocities at No. 6, the rise of Yahoo’s Flickr at No. 7, Six Apart at No. 10, and the presences of Chinese sites like Baidu Space and 56.com. The real surprise, though, is document-sharing site Scribd at No. 16, with nearly 24 million worldwide uniques. 1. Blogger (222 million) 2. Facebook (200 million) 3. MySpace (126 million) 4. Wordpress (114 million) 5. Windows Live Spaces (87 million) 6. Yahoo Geocities (69 million) 7. Flickr (64 million) 8. hi5 (58 million) 9. Orkut (46 million) 10. Six Apart (46 million) 11. Baidu Space (40 million) 12. Friendster (31 million) 13. 56.com (29 million) 14. Webs.com (24 million) 15. Bebo (24 million) 16. Scribd (23 million)
With all that scope for reasonable disagreement, is there anything we can all agree on? How much of the hierarchy in the medal table is indisputable, and how much depends on your point of view? So we want to say that one country has done strictly better than another if the medal score of the latter can be transformed into the former by a sequence of medal additions and medal upgrades. A bit of thought shows that this is exactly equivalent to defining a partial order on triples of medals, in which a triple (G,S,B) is considered at least as good as another triple (g,s,b) if and only if it satisfies the three conditions * G ≥ g * G + S ≥ g + s * G + S + B ≥ g + s + b