This is aimed more at companies signing up rather than individuals, but a company called Security Innovation has a product that kind of gamify's (sp?) hacking vulnerable websites: https://www.securityinnovation.com/training/ (the cmd+ctrl training)
They have a couple of fake websites that have a bunch of vulnerabilities of varying difficulty and you get points for exploiting them.
I am not affiliated with them, but saw a demo once and thought it was cool.
As noted by another commenter, they employ 500k people and execute on thousand of projects per year. Most of those projects are likely success stories to some degree.