.04 a click is pretty horrible. Its not even worth your page space for that and you'd be better off attempting to find someone else to advertise on your site, maybe on a monthly basis. You should also try to filter out the low paying advertisements, and decreasing the number of ad units on the page to increase your CTR and eCPM if you do it right.
congrats, the amount for 160 clicks is not bad, but could be better Depends on your niche and keywords
If those clicks come from the U.S., they would have been translated into higher pay. If those clicks are from shareasale, the earning would be much, much higher.
Web & Graphic Design tutorials and articles.. problem is it's hard to get high in the search engines for that particular niche.. but I'm slowly getting higher. (there's a link in my sig if you want to see the website).
It really depends on your niche.. one of my sites averaged something like 7 cents a click.. other sites have average over a dollar a click on occasion..