Hundreds of clickthroughs per user

[JohnFF]

Although a bug has been created for this issue, it's important to establish a few more facts surrounding it first.

Has anyone else had an issue where they sent a CiviMailing and the clicks on a single link by a single user were in the hundreds?

[shayaknyc]

We've been looking through some of our logs and have similar concerns. We have two theories:
1) multithreaded downloading through BIS servers?
2) forwards of the email to multiple recipients who all download and maybe also forward that email along?

[petednz]

my conclusion was 2/

ie the email got fwded around another network resulting in lots of clickthroughs recorded against the original recipient

[shayaknyc]

We're waiting for the next opportunity to send out a mass mailing and then add some google analytics link tracking to the links. We are going to pass their CiviCRM internal contact ID as a token in the URL with the link tracking so we can then try to gain some insight into who's forwarding their email and which IP addresses their internal ID is using to click on those links. This will, hopefully, provide some additional data to consider why the click rates seem to be so inflated (or, accurate).

[shayaknyc]

Some more insight into why the click rates seem so high. We've noticed that the number of clicks when we have a link that links to a PDF file is directly proportionate (by what degree, I don't know) to the size of the PDF. The larger the filesize of the PDF, the greater the numbers of downloads. Additionally, if the link text of the PDF link is NOT the full URL of the download, the numbers drop drastically versus the same email where the link text IS the full URL of the PDF download - both these factors seem to lead to some form of automated downloading. Additionally, if you just look at these tables in the MySQL DB:
civicrm_mailing
civicrm_mailing_trackable_url
civicrm_mailing_event_trackable_url_open (<-- this at least timestamps each click)

You'll notice that there are quite a few "simultaneous" downloads per timestamp of any given trackable URL. For example, it doesn't really make sense that a recipient will download a PDF 8 times in the same second, even IF they forwarded the message to others. I'm wondering how Civi is capturing these timestamps in civicrm_mailing_event_trackable_url_open ? Since these numbers are clearly not all that accurate. Would love it if one of the devs are able to provide some insight into this....