web caching / browser caching and traffic stats

does it lead to underreporting of visits (sessions)

[wolfgang]

Maybe this belongs somewhere else but the vast majority of my budget for PPC is with Google. Can web caching and browser caching lead my server-side analytics software to underreport site visits, but still deliver paid ads? I've used Google heavily for a while and often my paid Google clicks is almost equal to what my analytics program shows for total visits. I realize I might be experiencing click fraud also, but I need to know if caching could lead to this as well. Thanks.

[larryn]

wolfgang,

Caching can be a cause of under reported requests to your server. However, unless most of your sites visitors have modified the settings in their browser to never check for a new page, you should be seeing a mix of file downloads (status 200) and file status checks/download if new (status 304). While each tracking software is different, all should be able to properly process the 304's as part of a visit.

When you say 'still deliver paid ads' - those ads are delivered by Google, so your server will only see visitors who click on the ad. The best way to ensure your tracking PPC ad campaign referrals properly on your site is to use a tracking URL (www.xyz.com/index.html?ref=GoogleAd103), or an ad campaign specific landing page (www.xyz.com/googlead103.html). Personally I prefer the tracking URL as that string will only appear from the PPC referrals whereas a landing page could be spidered, bookmarked, etc.

Hope this helped,

Larry