Hi,
I have not been able to understand as to how one can get some one to come to a parked domain to make some revenue from domains not in use at a particular time. I have few domains registered some times back but could not find time to work on development of these. So was just thinking if using google script / parking these at google dns can help in earning some revenue, Not convinced though.

I think you'd better know the relationship between parked domain and addon domain to achieve the purpose about the revenue.