For the first time in my life I've launched a web site/app that isn't mostly popular in the United States. Yay!(?) Not that I care or that it matters but it's worth noting. For some reason it's currently most popular in France, followed closely by China and United States is not till the 5th place.
Of the United States visitors I'm not surprised the California bunch is more prominent. The service is quite new and quite technically interesting for people in the industry so I guess a lot of those visitors are Silicon Valley type folks.