More importantly, his signal-to-noise ratio is very high. Obviously, being very narrowly focused helps a lot with that. But it's nice to know that every post he makes is going to be worth my time. Most bloggers are very hit-and-miss, such that 1-in-10 (or at most 1-in-3) posts are really good, and the rest range from filler to kinda-interesting. Gruber doesn't write a whole lot, but nearly everything he writes is good.