Why Is Referral Spam a problem?

Well, there are two reasons.....

1. It simply wrecks your analytic data. You're not seeing a true reading of visits with these in there. You're number of visitors is inaccurate, their country of origin is wrong and how long they spend on your website can be skewed dramatically.

2. It can be a burden on your website and resources.

Beyond that, it's not too harmful. Referral spam won't install infected software, leave crap behind or deposit malware. Wealth Affiliate servers block all that anyway. It's part of our package here. It simply can leave a "footprint" and makes our Google Analytics about useless. It certainly can hurt your bounce rate as each referral spam visit is 0.00 seconds.

Why isn't Google stopping this?

Well, they actually Are working to prevent it, but they are keeping their efforts kinda hush-hush. They don't want to publicize this issue and inform folks of how they will block it, because the spammers will use that information to get around their defenses.