We've chosen these based on a combination of user feedback/demand and general "EveryBlockiness" of the cities. All three are really great, vibrant places, with plenty of interesting news and public data available at the block level. If you live in these cities, or have friends there, please take a look and help us spread the word.
Another major change to our site is our new home page. Now that we're in eight cities, we've redesigned it to accommodate the longer list.
We'd love to hear your feedback about these new cities, our previous cities, or life in general. Drop us a line at feedback at everyblock.com.