Today, Google Analytics is telling me that, over the past two days, there's been a surge in traffic for sphericle.com, where I occasionally post music that I've made. The site usually gets a few hits per day, but on Friday it had 60 visitors, and Saturday saw 180! Great news, right? I wondered, how did this happen? Where are these visitors coming from? To find out who was bestowing this extra attention on me, I went to the Traffic Sources tab in Analytics, and set the date filter to just show me stats for Aug. 29-30, the days that had seen the increase in traffic. What it showed me was pretty confusing: the top 5 referral search terms over those days didn't seem to have anything to do with my site. And, the second biggest referrer to my site (behind Google) for those days was a blog at the Guardian UK website. I looked up which pages at that blog were linking to my site... Analytics showed that there were a couple. I visited those pages and sure enough, the blog was a music blog. BUT, I couldn't for the life of me find any links to my website on those pages. Things were seeming very fishy.
Next point of investigation: what were all of my new visitors looking at on my site? To find that out, I went to the Content tab in Analytics. The majority of the visitors were going to my home page, OK. But beyond the home page, the URLs they were visiting at my site didn't exist. So, Google was directing people to my site based on search terms that had nothing to do with my site, and it was directing them to pages that didn't exist on my site. That would seem like a pretty big mistake on Google's part... unlikely.
Had my site been hacked or something? I looked through the HTML on my site, and didn't find anything that looked funny. Then, I got a bright idea... I did a google search for some of the terms that were supposedly driving people to my site, and visited the top hit. What did I find? A music blog in the UK. I looked at the HTML for the home page on the site and I found my answer: they had (accidentally?) put in MY website's Google Analytics account number into the Analytics tracking code on their website. The result was that my Google Analytics account was recording all the traffic to their site. And that Guardian UK music blog that was linking to my site? Well, nope, it was linking to this other website, which is why I couldn't find any links to my site on that Guardian blog.
So what do I do to fix it?
First, I sent an email to the website that's incorrectly using my Analytics account number, telling them about the mistake. They'll probably be happy to know about it, since they're probably seeing a flat line when they go to check their traffic stats right now.
But even if they don't do anything about it, I've gone ahead and added some filters to separate out my real traffic from their data. For now, I've added filters like the ones I described in an old post (Clean Up Your Stats by Grouping Hits from Other Domains), so that I can separate things out while still seeing if that other blog has fixed their mistake. If they don't fix it, I'll eventually just replace those filters with an "Exclude all traffic from a domain" filter, to squash the problem altogether.