HarperCollins is the latest publisher to say that it will delay the eBook verions of some of its new titles. From next year the News Corp-owned publisher will delay the online release of five to 10 new books each month for between four weeks and six months.

This will give it a chance to sell hardback copies of new releases at far higher prices than the $9.99 that most new eBooks cost.

This raises several questions. Will readers wait for the eBook version leading to less critical mass in the sales charts and less visibility? And will having no eBook at the critical launch time hurt overall sales, given Amazon’s incredible stat now that according to Amazon CEO Jeff Bezos:

“For every 100 copies of a physical book we sell, where we have the Kindle edition, we will sell 48 copies of the Kindle edition.”