A recent survey by Mochi Media shows that Flash game developers are making noteworthy profits from simple web-based games. Of over 1,100 developers and publishers surveyed, approximately 16 percent make more than $1,000 a month from Flash games, and the top 1 percent make more than $25,000 a month.
The Flash Games Market Survey (conducted in July) is the first comprehensive study of Flash developer demographics, and shows the percentage of developers making money from Flash games is much higher than other markets like blogs and music. A majority of developers surveyed say they monetize their games through ads, micro-transactions, sponsors and/or brand licensing.
More than 1 billion people play online games each month according to ComScore, but only 2 percent of Flash games are played more than 10 million times in their lifetime. On the flip side, a staggering 30 percent of Flash games are played fewer than 200,000 times. You can read more from the study on VentureBeat.