If you have selected 'good' niches it isn't that hard to get on Google's first page in around 6 weeks. If you made 5 websites based around terms that get google searches but aren't hugely profitable (don't have heaps of authority sites on Google's first page) you can easily make %5 a day from Amazon.
For instance one could be howtoflowerarranging.com that has seven articles on it, each based around a subniche how to do flower arranging - eg. howtoflowerarranging.com/rose-arrangements.php - that each have over 800 exact searches on Google a month. Once you have made the site every day create two 500 word unique (spun) articles based on flower arranging and upload one to a web 2.0 linking back to your site, Like:
Squidoo
Posterous
Blogger
Wordpress
Tumblr
wetpaint
Weebly
Wikispaces
Wikia
Then upload the other to an article directory linking back to your site and to the web 2.0 article, like:
Ezine
Goarticles
Do this every day while also doing blog commenting and other simple linkbuilding on a small scale and you should be ranking on the first page for heaps of searches related to flower arranging (for instance) within two months.
The final thing is to have LOTS of affiliate links back to Amazon, with many thumbnail pics that link to Amazon. That way you will have heaps of people visiting your Amazon links and a certain percentage will buy something. This tactic will eventually get you to $5 a day, I did the exact same thing as above earlier this year and easily made $5 a day from it (needed more money so I gave up on that 'method' but if you're willing to work hard for $5 a day it will work).