On 2 occasions now I have paused an adwords campaign. Each time I recorded the associated adwords stats after the end of that particular day. When I checked again about 6 hours later the stats had changed. The CTR had dropped by 30% (from 6% to 4%) and the impressions had increased by 30%, while clicks remained static.
This campaign hardly ever produces less than a 3% CTR so how could I rack up an extra 1000 impressions with no extra clicks on 2 occasions? Do Adwords Select impose a penalty for not running an campaign for a full day?
It could be that your CTR is a lot higher on google's own site than on their "partners". When you pause, I believe they stop it immediately on google, but it takes a while to propagate to other places.
I still have the occasional referral coming in from ads I canned 3 weeks ago - unless someone just bookmarked the entry page.
It also occurred to me that perhaps Google never charged me for any clicks made after I paused the campaign, and before they actually paused the campaign. They could have deducted the excess clicks but not the impressions.