On a similar note, one must wonder to what extent those who tweet are even local. For Napa, CA, which is mentioned in a comment, that would probably not be the case. Another example is Nevada, which, according to their map, must be something like the second happiest state in the union. I live in Nevada, and I am indeed very happy, but that's because I live in Tahoe, a rather atypical corner of the state. For Nevada as a whole, I am sure the result is due to things like tourists in Vegas going ga-ga over all Das Blinkenlighten, or gamblers tweeting when they win but not when they lose, the latter being the default.

I agree with you. In addition, they forgot to consider Twitter's use as a marketing tool for small businesses. Typically, small businesses tend to use happy words and phrases to describe their products. In addition, social networks are "generally" happy places. I don't think I have come across individuals using social networks as places to vent their sadness for long....

There is little correlation between onehappybird's happiness map and maps of suicide rates in the US.