We are currently running piwik on our site and doing Adwords campaigns. In all of my Adwords ads, I have the parameter "?pk_campaign=adwords" on all of my ad URLs.
The problem is, under piwik campaigns, there are far less conversions and visits than there are showing in Adwords. So it's counting some conversions at least, but definitely not all. It does not look like my Adwords pixel is firing wrong--it's showing valid thank you page URLs with unique IDs for every conversion it's counting.
We have the session time in piwik set to 4 hours as detailed here: http://piwik.org/faq/general/faq_36/
Actually, that might present another question, as that page says to override that line in the config.php file, but the "visit_standard_length" line wasn't even in there initially, so I am not entirely sure if the session time is set to what I want it.
What I need is to make sure the pk_campaign parameter is "sticking" to the user, even if he spends more than 30 minutes on the site.
Or if session time isn't an issue--what could be causing the pk_campaign parameter to not count some conversions?