At one point, the Jenny Craig weight loss company was running ads with the tagline “lose all the weight you can.”

All the weight you can?

How handy: a promise impossible to break!

Now here’s another: according to Damian Whitworth in the London Telegraph, lulu.com will turn unpublished writers into “potential J.K. Rowlings.”

But — unpublished writers are already potential J.K. Rowlings.

Lulu.com’s found, Bob Young, had his own brush with J.K. Rowlings potentiality.

The idea for Young’s digital publishing business came when he wrote his own book about Red Hat [the open source software developer he co-founded] to counter adverse media commentary on his company. The book sold well, about 20,000 copies, but he was disenchanted by the way it was edited, the tiny amount he was paid after the publishing house had stripped out costs and the enormous number of copies that languished unsold.

I think lulu.com is a wonderful company. If you have a niche book with a clearly identifiable market, easily and cheaply reachable through a manageable marketing campaign, lulu.com is definitely the way to go.

But does anyone really think that the only thing standing between a given writer’s obscurity and his Rowlingsesque success is the physical production of his book?