Domain Parking, How to optimize it?

So i have seen a few threads on here with people talking about domain parking, most people are saying that it is not worth it, I was wondering has anyone found a way to make any decent money with it? creating backlinks or anything like that? I Have acquired way to many domain's that i do not know what to do with, and i have had no luck trying to sell any of them, most of them do not get any hits, does anyone have any tips to actually making money domain parking? if so please share! it seems like if there was a way to optimize those domains to get regular traffic it could
potentially make a lot of profit, If you had enough domains parked that is.
Thanks Guys

I think it depends on the traffic and keywords. Low paying keywords you should use CPA instead.

sorry still new to all of this can you explain the CPA process to me please?