GOOGLE ANALYTICS: What is referral spam?

The majority of referral spam never actually visits your website, but it still appears in your reports as legitimate traffic and affects total sessions, bounce rate, time on site, conversion rates and more. On small business websites, this traffic can account for over 60% of daily sessions, which causes major problems in month-to-month reporting. If this traffic never visits your website, why does it show up in Google Analytics? Google provides a developer tool called the Measurement Protocol. Among other legitimate uses, this allows developers and businesses to track the behaviour of their customers from a wide variety of different offline data sources and send that raw data to their Google Analytics account. Unfortunately, this also opens the door for crafty spammers to force raw data into Analytics accounts by randomly attacking UA tracking codes, completely bypassing the website.