If you ever had been in Russia you probably noticed that there are a lot of book sales in Russia. Before, in Soviet times, they had called Russians "The most reading nation of the world" for their passion to read.
Nowadays, people still fond of reading even under the pressure of dvd/internet entertainment pouring on the heads from everywhere - in good old Soviet times they had no of such available so reading was the only way out to get some fun.
The quality of reading material has changed also a lot. If before it was mainly classic literature or some modern novels carefully picked by Soviet censorship for not having something unwanted in them then today people more often read low-level detective stories or fantasy books which are being created at a great speed of thousands new titles every week.
So all of those go in great competition for readers minds and attention. They sell hundreds of books in some totally weird places as just on the street or in the subway or just on a sidewalk. The brighter the cover the more chances that a passing by soul would spot some new shocking story of Cyber OMOH fighter stuck in 2020 with his new BHD-9000 gun and a mission to save the princess.
Today we have some of such illustrations for those kind of books made by Russian illustrator Leo Hao. You have a lot of chances seeing his works at such book selling points in Russia.