I heard someone saying $68 per 1000 impression in another post with $150,000 minimum puchase and I nearly fall down from my chair!
Is that $68 for 1000 unique impression or raw impression. I can't even think how scary it was if you told me it is raw impression where a visitor search a term and view page 1, page 2 and page 3 and is counted 3 impression!
Can someone answer me
1. Unique impression or Raw impression 2. Do they show your Impression to Click Ratio? 3. Do they tell you how many clicks are generated?
I don't actually do premium ads with Google, but if it follows what I've seen with AdWords they are (in almost all cases) not 'unique' impressions at all.
Try testing it with a low-impression keyword and you'll get a good idea. If a visitor (a Google-Cookied one I would guess) refreshes a SERP page very rapidly it might not count the ad again, otherwise it will.
(For the side-answer of what will constitute a billed 'click' for AdWords -- I have a good idea as someone decided to attempt to spam a keyword I'm in, but I'll decline to answer.)