Does it make sense to use a 1x1 pixel image to track page impressions? This is how an ad server is determining page impressions and I'm not sure if it's working because it seems to be very low. If this image gets cached, will a request even be sent to the server which has the image? If not then it would be seriously under-reporting the number of impressions. Thanks.

Hello,

I would assume that the image must be dynamically loaded:

http://www.site.com/image.php?id=3434

This will count the image impressions correctly since the image is not cached but rather outputed to the browser, and the browser checks for it everytime the page loads..

Peace,

if the image isnt cached (it probably wont be) then the company will still probably only count 1 hit per ip for a given period of time.. ie 1 computer cant rack up 1000 hits

The image is loaded as a regular img, not dynamic at all.

the company will still probably only count 1 hit per ip for a given period of time.. ie 1 computer cant rack up 1000 hits

Well if it's 1 impression per minute or something I don't have a problem with that, but if it's cached on the client or on proxy servers, it would be cached for a very long time, possibly even days and longer.

So this doesn't seem very fair then. OK, thanks for the input.