Mushroom Publishing is offering several 1st in series sf/fantasy & historical and mystery novels free with coupon, including backlist items by Alan Burt Akers (originally published by DAW) and Moyra Caldecott. They also have 75% off a very few selected books.
Doranna Durgin (fantasy & romance, published by Baen & Harlequin) is offering three of her Baen novels free to download, several of her short stories free with coupon, and 25-50% discounts on many of her works (including backlist from Baen & Harlequin).
Gord Rollo (horror, published by Dorchester/Leisure) is offering a novel and some short stories free to download or free with coupon, and 25-50% off selected works, some of which I recognize as being his ex-Dorchester backlist.
Keith Brooke (sf, owner of Infinity Plus imprint which reprints many prominent sf/fantasy authors, forgot who's published him but he's got a prominent ISFDB entry which I'll edit in later) offers several short stories free with coupon, and 25-50% off selected works
Stephen Goldin (sf, fellow MR member author, don't know who's published him but will edit in ISFDB entry later) offers 25-75% off many of his works
Vivi Anna (romance, published by Samhain or Ellora, I forget which) offers several paranormal shorts free with coupon or to download
Cynthia Wicklund (romance, has had a story appear in one of those Mammoth anthologies) offers two novels and a story free with coupon or to download and 25-50% off selected works
Marina Oliver (contemporary & historical romance & romantic suspense & romantic historicals, published by Robert Hale among others, also under pseudonyms which she generally lists in the info of her books) offers 25-75% off selected works. She has a very long catalogue and you'll have to do a lot of digging to see the deals.
Phoebe Matthews (urban fantasy & romance, published by Dell & Avon, among others) offers a short story free to download and 50% off selected works
Those are the people I remember spotting earlier this morning when I had a quick look through the obvious categories. Further contributions welcome.