Most fans are obeying the honor system and sending King $1 for each installment downloaded from his Web site. And some still are sending in extra bucks to cover freeloaders.
But the latest numbers showed that just less than 70 percent of those downloading The Plant paid for it. King has set 75 percent as the minimum for him to continue after part three, which will be available on his Web site Monday.
"We're a little confused about what's going on with that," said King's assistant, Marsha DeFilippo.
The story, begun and based in the 1980s, is about a vampire vine that takes over a publishing company.
King's people still were trying to nail down how many have downloaded the first two parts successfully, so the payment estimate could change. DeFilippo said 172,004 people had paid for part one and 74,373 people had paid for part two by Sept. 13, the last date figures were available.
In a message to readers posted on his Web site, King speculates on possible reasons for the decline, including a slip in interest and technical difficulties.
"There is undoubtedly some thievery and bootlegging going on, but Marsha and I believe the real problem may lie elsewhere," King said.
Some readers have downloaded the story two or three times to different formats, such as PCs and handheld electronic organizers, but paid for only one download. Similarly, people have "lost" the story in computer crashes and downloaded again without paying, DeFilippo said.
Another is that many struggled to download the second part. Though no specific problem was pinpointed, King's camp has since switched its download company to Amakai Technologies and has eliminated much of the difficulty, DeFilippo said.
E-mails were sent to readers who paid for part one inviting them to take part in a survey about the experience, and 87 percent of the 28,000 people who responded said they didn't realize part two was available. About 96 percent said they would download part three, she said.
King said part three will be the last if the payment numbers don't go back up to 75 percent. But there is still hope for hooked readers.
He is considering offering subsequent parts with a pay-first requirement "as a response to those who have been honest," DeFilippo said. Also, if he continues, the parts will be longer and will cost $2 instead of $1. After part eight, they'll be free.
King has written through part five and is getting attached to the story.
"He's gotten excited about it. It's like visiting an old friend again," DeFilippo said.