A while back we were convinced to add site search with G adsense results to our site. We had previously used another annual fee based search engine. I was doing a final comparison as our fee is due on the old one and we were planning on getting rid of it, and I noticed that the number of page results for various keywords on the old search engine was higher than G's (9 vs. 5). Upon even closer inspection I discovered that G was displaying even less under adsense search than when searching google for "site:mydomain.com keywords" (5 vs. 10 - somehow they found one more than our old search engine). I made sure to click the "show extra redundant pages" link in all instances.
Anyone else notice this suppression? Does G think that by making only half of the applicable pages available on the local site that users will click to go to other sites and they can collect a commission? This does not bode well for us removing the old search engine and replacing with GAd when it is keeping people from finding additional pages of information on our own site.
