I am curious which topic are your site is in? Just a general topic is fine...computers, entertainment, health, fitness, programming, cooking etc.?
So many times you hear the same old stuff...build a site about something you are interested in, add a page of content a day etc.
The fact is not all topics are easy to make money with. I'm sure my webpage about my 92 Miata will not make me much money. However site that speacializes in Italian cooking may have some potential.
If your making that much with Amazon alone then it's pretty impressive. Amazon has a reputation for not being the best place to make money. Are they product links or are you using the web service?