Causes of Missing Referers in Web Logs?

[pete532]

20% of my landing page hits from Overture do not have a referer in my web logs. This strikes me as high.

The landing page URLs include tracking parameters, so I doubt users are typing in the URL.

And I deal mostly with people who would not know how to turn off referers in their browser or firewall.

So there has to be another explanation. Maybe...

1. Spoofing by click fraudsters
2. Referers turned off by default in a very popular browser or firewall
3. Clicks from an AOL-like ISP using proxies
4. Something else...

Any ideas?

Pete

[pete532]

I should add that my equivalent number for AdWords is 16.5%. My figures are based on a large sample, and they're statistically signficant.

Pete

[gregbo]

Could be any of those. Without more information, it's hard to say.

[sundae]

5. Editors who hide the referer sothat u cannot complain against them