Robsp - 6:54 am on Oct 11, 2003 (gmt 0)

My experiences are quite different. On a global campaign with only exact matches both CTR, CPC and positions stayed unchanged. There was a slight traffic dip when they switched it on but everything is back to normal again.

My (local language) broad matched campaigns (with lots of negative matches) have gone down in clicks with about 20% mainly because the average position dropped a little.

I guess it is still a matter of exact matches and writing very targetted and distinct ad text, something that your typical dick and harry can't do anyway.