Unique contents, 38k Alexa, PR3: How much from adsense per month?

I have tried my best to optimize and I think I have tested all types of ad placement and color scheme even rotating postions with different color pallette but my monthly earning from adsense on my blog is still low. I mean 38k alexa, PR3 but last month I got only 3$, 5 days this June earned only $4.

What is my site problem? Does the niche affect this or my site has been affected by smart pricing? I could not explain and I hope you guys can share your advice?

Thanks in advance
T

 

I think you need to change somting

1.position of ads
2.color of adse
3.test what ads you got more click

 

3.test what ads you got more click? What do you mean this?

 

You set up your ads in channels, that will tell you which ads are clicked. For example, if you have an banner ad on the top of your page, you set it up in a channel and you'll see how many clicks that specific channel has -> You'll see how many times the banner has been clicked on

 

hard to tell need to see the site first?

 

Thanks, let me try this and see. Really appreciate your advice