Yes, I have had great success with this, I even wrote a guide about it found at the link in my personal profile here. The whole thing works off of a loophole that greatly increases the revenue you can get with these sites. Ziddu does pay, I get paid monthly from them, however lately they have been setting off the google attack site warnings, but there are other sites to choose from should you take in my instructions and apply my guide.
Takes about 20 minutes per use, and each time is the potential for anything, but my implementations are always averaged at about 15-20 dollars each per month. Oddly, downloads only increase in speed, I would have thought eventually the 'market' for any given file would be dry once 'everyone' got any given said file, but using my method I've learned that there are a whole lot more people in the world online than I expected.
This is my first post, I've been a often times lurker for a while, and I would never go into detail about this anywhere else, but I like the atmosphere here and want to give a little.
I sell the book with the ability to do referrals, and those work out well (obviously) because the traffic I get is usually recommended. For this forum, anyone who wants to make easy paypal payments (half/50%), PM me and I will give you your own link (tell me what it should be called - screenname, actnow, bonusoffer, whatever). The site converts pretty well (about 12/100), but I am beginning to think it could use some tweaks, or better preselling from affiliates (there's only a few out there, and only a couple of them have done bang-up jobs).
If you can get traffic coming - real traffic, don't time out my comcast hosted site sending bots

- I will treat you like a paid affiliate (details at page) and give you a free copy of the book when you make your first referred sale.
The page is 'laser targeted' to bux/gpt/etc users, mainly because in my opinion it vastly improves upon any of those other methods, and with the twist I have created it is even better.
PM me for details I guess, I'm new here so I don't know if I will be subscribed to the post automatically, etc, and wanted to start out with a bang so someone can buy me some crack some time (that's an awesome feature, delivery is king in that respect).
I refrained from posting direct link etc so that this post is more ambiguous to searchers, this info is really only being shared with BHW members - I hope that this confidence leads to more - cheers, great site.