Preparing to filter spam content I've analyzed the data and found some direct and referral traffic where the hostname is (not set). I assume the direct traffic is spam as it has a bounce rate of 100% and an average session duration of 0:00.
But I'm not sure what the referral traffic is. This traffic has a bounce rate of 76.43% and an average session duration of 00:00:48. What can this traffic be? Spam? An error in the google analytics tracker implementation on the website? Web Crawler? ...