While Baym's work is highly academic, strongly grounded in theory, and chockfull of references to important works from a broad range of cultures (Finnish cell phone use? Politics of friending on Korean social networks?), above all, it's readable. I literally couldn't put it down, and I'll definitely want to use it as a text for undergraduates and graduate students alike.
Baym is ever-reasonable, balanced, personable, striking that fine balance of authorial presence between a phony and stilted objectivity and "TMI." Every concept she introduces is fairly, clearly presented, whether she agrees with it or not.
If you're looking for a good scholarly introduction to new media, or an STS work in media studies, or just an example of academic writing at its best, this is the book.