FWIW I tried it shortly after it launched so a bit after ~2005, maybe 2007 because I read about and honestly found the prospect, from a dataset creation or improvement, quite interesting. I think I heard about it from a research paper that distributed its work that way.
Well it did work, in the sense that I managed to complete some tasks. I don't think I ever collected the money/credits back then though (simply because it amounted to so little). What I can attest though is that... it was debilitating. If you think your office job is boring then splitting it in way smaller tasks where you have no autonomy is absolutely terrible from a worker standpoint.
I initially was hoping to use it in order to work on providing a service over a dataset but understanding first hand what it takes to make it happen made me stop. It radically changed how I saw supervised learning since, and sadly not in a good way.