BetterThanBanners will give Amazon vourhers to webmasters who display their advertisers banner ads. You'll receive a £10 Amazon.uk vourcher for just signing up as a publisher of BetterThanBanners and then you'll get a £5 vourcher every month for displaying their banner ads on your website. You don't need to have a high traffic site to join
their network. All you need is a mini site with English content. BetterThanBanners has 2 webites:
The difference between the above 2 links is that the .com one will give you vouchers for Amazon.co.uk (pounds) and the .net one will give you vouchers for Amazon.com (dollars).
You can also make money referring new publisher who then place a banner on his site.