Daily Ebook Deals Gain Traction

Every day, the company BookBub.com sends out more than 7 million emails pointing consumers to ebooks that cost as little as 99 cents each and free titles as well.

A host of big and independent publishers list titles there, including New York-based Kensington Publishing Corp. The idea is to entice readers with a bargain, so they get hooked on a new author or series and eventually buy full- priced works.

"We know we might be shooting ourselves in the foot," says Mr. Zacharius. "But I can't resist because it's such a good way to stimulate sales."