Initial reaction: Great read. I was impressed with the way Clark broke down the advantages to writing short and taking inspiration from shorter forms of text in order to improve one's writing. Some of these cues I've already incorporated in my own writing without realizing it, but it also gave me pointers as to how to think better using those skills.
I'll admit that I haven't read that many guides to economizing writing in the contemporary spectrum, but Roy Peter Clark does a fine job of giving great pointers on how to do so in "How to Write Short: Word Craft for Fast Times." In the narrative, he explains just how our society is full of fast writing - from Twitter, to song lyrics and poetry, to status updates and quick notes. He explains that knowing how to utilize measures of quick writing can actually help improve your writing in general, and uses the narrative to explain the whys and hows of doing this.
I'll admit much of this I knew from my own writing style, because of a love for poetry and music, but he does a great job of walking through each of the different facets of writing short and how it is useful. He also shows how people can be inspired by short writing and provides tips at the end of each chapter on how to put it into practice. I would rank it among my favorite guides, much like my read of his "Help for Writers", to writing and would highly recommend it.
Overall score: 4/5 stars
Note: I received this as an ARC from NetGalley, from the publisher Little, Brown and Company.