Groupon ran an experiment to try and figure out where "direct" traffic that appears in analytics programs is really coming from. Gene McKenna, director of product management at Groupon, wrote a blog post about the findings for Search Engine Land.
McKenna leads Groupon's organic search efforts. He says they completely de-indexed their site one day "for the sake of SEO science" for about six hours. During this time, they examined organic search and direct traffic by hour and by browser to any page with a "long" URL. He gives this one as an example:
While traffic "attributable to SEO efforts" dropped to nearly zero, "direct" visits dropped by 60%. That 60%, he says, is really organic. It was on Groupon deal pages, which have long enough URLs to make it unlikely that people were actually putting them in manually and new enough that users were unlikely to have them bookmarked or remembered in auto-complete.
They also hypothesize that SEO isn't the only channel losing traffic credit because of browsers hiding referrers. Link referral campaigns could be suffering too, according to McKenna.
He doesn't recommend deindexing your site for your own testing. Check out the rest of Groupon's finding in the original post. He shares some interesting graphs.
Image via Groupon