The Wall Street Journal, in an article published yesterday, estimated that about 20% of Netflix's more than 10 million subscribers stream titles, though Netflix spokesman Steve Swasey said the company doesn't disclose such figures, pegging the amount in the "millions."
I'm not sure why, if the figures are so great, they don't publish them. Could they be so bad they're afraid to publish them with so much riding on the streaming model. Possible. Probable.