My AdWords budget for my site is a max of $100 a day and my site is in the top 3 results in a hot niche. I usually use up my budget every day with an average cost per click of $2.00. This past week I've gotten twice the amount of clicks and click average is $0.08 not that I'm complaining that the price fell so much but what happened?
Could be lots of things...perhaps content network activity? Typically keywords don't drop from $2.00 to $0.08 per click overnight.
how many days was it running? My guess, content. Since content takes a few days to kick in, you were probably paying $2 on search then when content kicked in your CPC dropped to 0.08. Especially since you said you got 2 times the amount of clicks the other possibility, competitor drop out.
6 months it's been running for and didn't drop until recently. When I first started I was paying about 25 cents a click. I think I figured it out though my biggest competitors stopped running ads.
THat is quite the drop. I'm not sure that competitors stopping their campaigns is the answer though. Maybe your ctr went through the roof along with your qs?