1. Which type of search site is generating these impressions?
2. Lowering my CTR is not a good thing for me- Should I not use the search network?
hope this helps.
[edited by: jatar_k at 4:24 am (utc) on Jan. 24, 2008]
When you opt in to the search network, your traffic can come from thousands of sites that use Google as their search provider. The fact that you recieve more impressions is simply due to the fact that you are reaching a much larger user base. However, many of Google's partners do not provide the same quality of traffic as google does for a very simple reason: somebody who is seriously searching for something will use google, not a third party site 'powered by google'.
the best way to find out where your traffic is coming from when using the google network is analysing the referrer URLs in your server logs.
[adwords.google.com...]
[edited by: RhinoFish at 1:25 pm (utc) on Jan. 24, 2008]