I'll come clean. What has spurred the daily writing this month is NaBloPoMo--National Blog Posting Month. The idea hatched as a method to get people writing. NaBloPoMo parallels NaNoWriMo--National Novel Writing Month--but doesn't have the 50,000 (!) word requirement.
The challenge here is a daily post. I'm not yet halfway through the month but I am satisfied with my progress so far. A Stanford writing professor recently remarked that a blog counts as a writing practice. Getting the words out is exercise we need.