Yelp's international sites have been growing like crazy, with non-U.S. traffic doubling in the past year. Today, it is adding a fifth non-English international site, Spain , to its roster. (The other international Yelp sites are in France, Germany, Austria, and the Netherlands). Yelp is now at 50 million unique visitors per month, mostly in the U.S., according to its internal stats. ComScore shows 87 percent growth in non-U.S. unique visitors over the past year (Yelp's internal stats show more than 100 percent growth).