Yeah, 3 seconds isn't that long while the user is scanning the suggestions for what to type next, and not actually looking at the adds. Just guessing here, no hard data to back this up, but I can see this thing eating impressions at a vastly increased rate.
Suggest just got a whole lot more important for KW research. Maybe more important than the KW tool. My initial gut reaction.
How impressions are counted
When someone searches using Google Instant, ad impressions are counted in these situations:
The user begins to type a query on Google and clicks anywhere on the page (a search result, an ad, a spell correction, a related search).
The user chooses a particular query by clicking the Search button, pressing Enter, or selecting one of the predicted queries.
The user stops typing, and the results are displayed for a minimum of three seconds.
We recommend monitoring your ads' performance the same way you usually do. Google Instant might increase or decrease your overall impression levels. However, Google Instant can improve the quality of your clicks since it helps people search using terms that more directly connect them with the answers they need. Therefore, your overall campaign performance could improve.
uhhh... GOODBYE CTR - while this thing is new people are gonna play with it. Goodbye CTR, goodbye quality score.
FML
This is pretty shitty. I wonder what the threshold is google counting an impressions in time. I mean if the ad shows for 1.5 seconds and they count that as an impression, well that is going to piss a lot of people off.
I dont know why everyone is worried about impressions and CTR. If this fucks with Googles monies this will be turned off this week.
I bet CTR and impression adjustments from Google are reduced today maybe all week until they make sure everything is ok.
If they have to eliminate CTR as such a huge affect on Adwords it looks like they will do it. They want this bad and are rolling it out en masse.