We ONLY receive free digital copies of books in exchange for a fair and honest review — period. (thekindlebookreview.net)
As an aside I did a group newsletter swap that resulted in 360 emails in 15 days in exchange for free digital copies of book one. (draft2digital.com)
The store also provides free digital copies with the purchase of a physical one and other promotions like one free digital novel a month. (goodereader.com)