It depends on what niche the website is about.
Some website niches earn more than others.
Sites with niches such as Insurance,Finance,banking, etc earn more than sites in niches such as cooking,food,etc.
500 daily visits is not really enough to earn much anyway. I'd say once you get to at least 2,000 daily unique visitors you could earn $2.00 per day or a little more.
You need at least 10,000 or more daily unique website visitors to earn upwards of $20.00 $30.00 or more per day.
Keep working on that traffic.