email click thrus seeing strange results

i'm seeing batches of people hit the email click thru at the same time

[kvdheide]

To track activity from our email newsletters or campaigns, we use the unique id parameter at the end of the url to track click thrus. for example: index.html?id=1234

This has been relatively successful in measuring response rates and ultimately ROI on our campaigns.

In recent weeks, we've started to notice strange behavior. To illustrate: 20 individuals would click thru on the email message all at different times generating an activity log, then a day later the exact same 20 people, would all click at the same time in the wee hours of the morning (i mean a timestamp of "2005-07-08 01:48:49") - down to the second!.

Has anyone else experienced anything like this? The link must be clicked to generate the activity log. Browser caching? Spiders/crawlers? Server issues?

I don't even know how to search for this problem!

[larryhatch]

A wild guess: Automated spammers 'phishing' for valid email addresses? -LH

[kvdheide]

I'm not asking whether people on our own opt-in lists have been contacted by someone else claiming to be us.

I'm just interested in how a unique URL that has been previously clicked, is being clicked again in a batch with many others.

[Dijkgraaf]

What is the User Agent on those log entries?
It sure sounds like there is some sort of automated process hiting those URL's again. Is it identifying itself e.g. having MSIECrawler in the agent somewhere.