[Linda Buquet]

"Having said all this in general, if you are running a campaign for any length of time [a month maximum for me]"

I wouldn't say look at a time frame, I'd say need to look at # of clicks. Because a newbie could only get 20 clicks in a month and we wouldn't want him to scrap anything after a month, because that's not enough clicks to make a sale usually or enough data to even make any decisions. On the other hand a high traffic site could get 10,000 visitors in 3 days and if a campaign isn't working out after that much traffic maybe should re-evaluate, even though it's only been 3 days.