According to a UMass study, 31 % of bloggers spend 1-4 hours per day researching for and writing their posts, 65 % spend less than one hour.
One hour a day is a significant commitment in the busy schedule of most physicians and this explains why so many of them quit blogging purely for time constraints. If a remember correctly, Medpundit wrote that she could see 4 extra patients in the one hour she used to devote to blogging.
Link and image source:
UMass Study Identifies the Traits of Successful Bloggers. Micro Persuasion.
Behind the Scenes in the Blogosphere. Nora Ganim Barnes.