Charging back to the top of our list of bestselling titles on the Smashwords platform for the month of April is Diary of an Oxygen Thief, a novel described as Fight Club meets Mad Men, that was written by an anonymous author.

It's an exciting time for that still-anonymous author: After he or she sold the screen rights to Oxygen Thief to Gotham Group last month, the North American rights to the book were quickly snapped up by Jeremie Ruby-Straus at Gallery, the Simon & Schuster imprint.

But, according to Smashwords CEO Mark Coker, the third installment in the Oxygen Thief Diaries series -- which was not included in the deal -- will be released in October by Smashwords.

As per usual, romance is in the air at Smashwords. The rest of the top five is dominated by romance titles -- with Olivia Thorne grabbing a brace of slots with two installments in her The Rock Star's Seduction series -- while 16 of 25 total titles on the April list were romances.

Rank Title Author ISBN Genre Price
1 Diary Of An Oxygen Thief Anonymous 9781452409535 Fiction $9.99
2 Bounty Kristen Ashley 9781310258299 Romance $3.99
3 Fated R.L. Mathewson 9781310662317 Paranormal Romance $2.99
4 Rock All Night Olivia Thorne 9781940989075 Romance $4.99
5 Hard As Rock Olivia Thorne 9781940989099 Romance $4.99
6 Broken Silence Natasha Preston 9781301920686 Romance $2.99
7 Den of Sorrows Quinn Loftis 9781311050311 Fantasy $3.99
8 The Phoenix Requiem Richard L. Sanders 9781310594298 Science-Fiction $7.99
9 The Miracle Morning: The Not-So-Obvious Secret Guaranteed to Transform Your Life (Before 8AM) Hal Elrod 9780979019760 Self-Help $9.97
10 Beautiful Burn Jamie McGuire 9781310232152 Romance $5.99
11 Jase Geri Glenn 9781310728334 Romance $2.99
12 Broken Lives Brenda Kennedy 9781310235658 Romance $3.99
13 Mending Hearts Brenda Kennedy 9781311520401 Romance $3.99
14 Christmas From Hell R.L. Mathewson 9781310090110 Romance $2.99
15 Kindling Flames: Flying Sparks Julie Wetzel 9781634220163 Paranormal Romance $4.99
16 Sidebarred Emma Chase 9780997426205 Romance $2.99
17 Pieces of Eight Melissa Wright 9781465925046 Fantasy $2.99
18 Forever Chanda Hahn 9780996104821 YA Fiction $4.99
19 Underland Chanda Hahn 9780996104845 YA Fiction $3.99
20 Kindling Flames: Smoke Rising Julie Wetzel 9781634220446 Paranormal Romance $5.99
21 Players, Bumps and Cocktail Sausages Natasha Preston 9781311298089 Romance $2.99
22 Deep Skye Warren 9781940518435 Romance $4.99
23 A Second Chance Shayne Parkinson 9781452303871 Fiction $3.99
24 Kindling Flames: Burning Nights Julie Wetzel 9781634221849 Paranormal Romance $5.99
25 Mud and Gold Shayne Parkinson 9781452303802 Fiction $2.99

Correction: A Previous version of this story stated that the second installment in the Oxygen Thief Diaries series was due out in October. It is the third installment that will released in October.