Write a Book in 28 Days?

I just discovered a workshop that teaches one to write a book in 28 days; now I'm a bit of a pessimist; I believe anyone can write 10 pages a day, but the point is will there be a story of interest to readers? Those of us who write for fun or it's our day job, the tough part is after the first draft is completed; it's the re-edits and rewrites that require determination and skill.