I actually heard of this via the newsletter from Shepherd.com. The impact of changing your book cover on clicks - in a very specific test bed to readers already interested in your genre.
Anyway
What interested me was that:
The original covers were all done to a good clean standard - as in I wouldn't have leapt up and said done by an amateur.
Almost all of the remakes were paler/lighter/brighter than the original.
Anyway
Can a Professional Book Cover Double Your Sales?
Let's find out how much a professional cover design can affect book sales — with our strictly scientific experiment.
blog.reedsy.com
What interested me was that:
The original covers were all done to a good clean standard - as in I wouldn't have leapt up and said done by an amateur.
Almost all of the remakes were paler/lighter/brighter than the original.