Has anyone else heard of these sites? are they a scam? I've signed up for free, but ti seems the only way to get padi is to have a lot of referalls. =/ so..

 http://bux.to/?r=dakafal

Seems less scammy than other sites that claim to pay people just to surf the net (whilst being spammed with popups of course), the amount per ad is kinda realistic (1 whole cent, couldn't be much less) and you can request payment at a low amount ($10), so they're not banking on people giving up and never claiming because they can't reach the $1000 minimum claim amount.

Although, $10 one cent at a time = 1000 ads viewed, at 30 seconds each that's 8 hours and 20 minutes of time to get just 10 dollars, only just more than $1/hour.

Being able to get payed for all your referred people's ad-viewing as well means that (as you say) the only way to make decent money, like the amount they say on the front page, is to be at the centre of a large web of referrals. Since each person can only have been referred by one other, they pay a maximum of 2 cents per ad, so it's still looking non-scammy on the realistic economics front (there was one of these pay-to-surf things that couldn't possibly have had enough income to pay out)

But, since to make money each person pretty much needs to refer lots of other people, it almost becomes like a pyramid scheme (except without the layers above you - that's simplified down to the company being paid more than 2 cents per ad-view).

So its dubious, but probably not a scam would be my assessment, if you ignore the over-high amount they lead you to believe you can make then it's probably honest, but not really worth your time (unless you can convince a lot of other people that it is worth their time)