Over the past year, I’ve seen many people report that Twitter can send tons of traffic to a web site. Certainly I’ve seen first-hand how Twitter has become one of the top non-search referrer sources for Search Engine Land and for some other sites I oversee. But as much as you think Twitter is driving traffic, it might be sending even more that you’re unable to measure.
Consider this recent example. I wrote an article on my personal blog about the collapse of the Clear airport security program last night and how it seems likely that alternatives to it will also go away (TSA Stays Silent As Its Registered Traveler Program Melts Down).
The screenshot shows that Bit.ly had seen 343 total clicks to that URL through its system (when I did the screenshot), 339 of them coming from the shortened version I created. So Google Analytics ought to show me roughly that same number of people coming to the page from Twitter, right?
Nope. Google Analytics reports that Twitter sent 63 visits:
I know some visits from today have yet to be reflected in Google Analytics. That’s why you see the line drop. But I also know that those visits, based on my Bit.ly data, should be about the same as yesterday. In short, at best, Google Analytics is going to report I had about 130 visitors to the article from Twitter. But Bit.ly’s saying I had about 340 visits. Where are the missing 200 or so people? How come Bit.ly’s showing more than three times the visits overall to the page than Google Analytics does. I’ve seen this time-and-time again for various stories, sometimes with gaps of several thousand visits.
We’re also working on some predictive modeling techniques to screen out more bots and scrapers from our click totals.
You might be interested in this article from the MIT Technology Review — http://bit.ly/qrjrf — which shows that these kinds of metrics issues are an industry-wide challenge.
I plan to look at the issue more in the future, but I wanted to get a post out there now with my initial findings and see what others have to say (please comment below!).
Somewhat related, also consider reading this post from Bit.ly: Registered Applications And Better Click Referrer Data.