One of the things to watch, is that because they are in New Zealand, all payouts are in NZ$. If you check out www.ipower.com you will see they are making $100US per sign up. Not only that but a recent email to me suggested their lowest payout rate is NZ$1.50 (US$1.15). (At time of writing, I thought Affiliate Junktion paid per conversion, they don't, Affiliate Junktion pays per lead. Only Affiliate Junktion themselves know how many leads end up signing up)
If you put that together with the increase in people using keywords like "make money" through Yahoo or Google adwords resulting in a hight cost per click, its easy to see there is plenty of money for them, hardly any for you. (since writing that I have got my cost per click down to €0.03 for Affiliate Junktion ads)
Really the only ones making the money are Affiliate Junktion (maybe Affiliate Junktion isn't making money, see my latest Affiliate Junktion blog here) .