Does anyone have some tips as to how I can serve up my clients banners without them being blocked. I'm finding almost half the visiors to my site have Norton so with the blocking it sques the unique visit numbers?? Anyone??

Need to know a little more. What kind of system/program do you have running this?

I'm not sure how effective this is any more but many ad blockers look for certain filenames or references, so if you call your ads via a file like "banner.php" they assume it's an ad. The way to get around this used to be to rename all your filenames and references for the script you call the ads from to make them look like page includes etc.

Some image sizes are blocked too

Thanks for the help, it seems banners are a peice of cake for Norton and windows security to block in browsers. Short of redesigning our whole site we'll have to make adjustments...quite an eye opener. Will have to figure out another way to deilver value for our advertiser clients.
We are at www.saskatoonhomepage.ca