Ransom X is the first in the Legacy series by I. B. Holder. It was the first self-published book to crack the mystery novel bestseller lists on iBooks and Kindle in 2010. It peaked at 17th and has received over 1,400 reviews on iTunes, Barnes and Noble and Goodreads combined. It carries a 4-star rating and represents one of the first books that broke through into the public market after it was published only on digital platforms.
References
Ransom x Wikipedia(Text) CC BY-SA