Prolific has no income apart from donations given on this page.

I created Prolific in 2007 out of curiosity as to how Facebook worked; people liked it, a community formed around it, and the rest is history.

So, if you like playing Prolific, and you're happy to donate towards server costs and keeping things ticking over, here's your chance. Thanks to people like you, Prolific stays online and available to all.

— Mog Nesbitt, Prolific Developer