Fiona and I were trying to work out when we first noticed the start of referrer spam, it must have been early last year with the Semalt crawler. We saw it as an annoyance, but no real issue to remove with a filter or segment, if only we’d realised the deluge of spam heading to Google Analytics.
Now, some 18 months later there’s numerous articles around the topic of how to block referrer spam and lists are being maintained of the offending sites. The list I follow is Piwik’s and with over 280 sites it makes for depressing reading when we’re updating the Regex filters and segments across multiple GA properties and views.
What really frustrates me is the impact this has on website owners.