Your question's answer can be vary from Site to Site, Its depending on many factors that what your website offering and what is the market demand of these products on the internet.
I have one example which may earn the huge amount by PPC, The site type is discount coupons Such as www.couponcabin.com
these type of sites can easily earn $1000 in a month as new sites. But there are various ways to get.
For PPC marketing it is very important to select the very quality keywords with targeted region on market.