Hello guys,

Somewhere after the upgrade to 2.15.0 I got a nasty bug which drove me crazy. When a user is reaching my site in any other way than adwords everything is perfect. But when the visitor comes from adwords (which has /?pk_campaign at the end of url) it tends to generate lots of visits, sometimes as many as pageviews.

The thing that got me going crazy is that i could not reproduce this bug on demo.piwik by directly entering the forum with /?pk_campaign in url. It seems to work fine there.

I have tried everything:

• completeley erased piwik installation from server
• completely erased the database
• clean install 2.15 from scratch and also 2.15.1 beta, even in completely new databases
• lost my data of 2 years in the process, partially recovered monthly stats by manually entering values in database
• I also reverted to the clean javascript code provided by piwik settings with no heartbeat and no userid. On piwik forum the javascript code does seem to look different compared to standard one.

No effect. I have done all the above at least four times. I have concluded that there is something wrong with the way piwik sees a users reaching my site with ?pk_campaign (+1 visits) then going to another page normally (+1 visits) then for instance press back and once again is in the url with ?pk_campaign in it and hence (+1 visits). And so on. On the other hand, if you click the visitor profile you can see all these visit, piwik knows it`s the same visitor, but it just creates new visits for them one after another.

In the provided picture of a visitor reaching my site from google adwords you can see that some of the visits are non-clickable "adwbuc" other are clickable "adwbuc" (originating from my own site) with ?pk_campaign & long gclid when hover.

Having just plain text as the adwords campaign source also happened prior to 2.15 but rarely and also, never created the crazy visits rollercoaster.

Picture of 5 visits created for the same visitor in 7 minutes: