This series of blog posts reviews developments in contract cheating since 2006.
It also includes several new small-scale research studies which help to shed more light on the contract cheating problem.
Some that I think are particularly useful including examining how contract cheating sites attract writers and looking at the social media marketing methods that essay mills use to attract customers.
This blog post provides lots of details about contract cheating from discussions at Plagiarism Across Europe and Beyond 2017.
Some particular challenges related to how students perceive contract cheating and want to be engaged further with work in this area. There were also some questions raised about terminology, including from participants at a plagiarism conference who had not come across this before.