Are you seeing a big spike in “(not provided)” data in your web analytics’ referring keyword report? Here’s what’s going on.

Google announced, in mid-October, that it would stop passing referrer information for search engine users who are logged into Google (Google products include YouTube, Gmail, Google Docs and many others). Specifically, that means that your analytics software won’t show what keyword a logged-in visitor used to reach your site (unless it’s pay-per-click/AdWords traffic). You still see how much traffic came from organic search, and which pages visitors landed on, but not the specific keyword they used.

If you go into your analytics software and look at your Referring Keyword report, you will see a line that says “(not provided)” – those are all the different searches (combined) where Google stripped out referrer data.

This decision by Google won’t impact ALL your keyword data, only searches by logged in users; but the extent to which it’ll impact your data looks to be in flux.

That “feature” began rolling out on October 18. It appears that Google has begun rolling out this change more aggressively in the last few days. Other site owners are reporting a big spike in the percentage of keyword traffic that is “not provided” – we’ve seen an increase as well, although the percentage (of “not provided” vs. total keyword data) is still very small for the domain as a whole.

Different types of sites are going to see varying degrees of impact. Sites whose visitors are heavy users of Google products (e.g., tech blogs) will see a bigger impact. Sites whose audiences don’t tend to have Google accounts will see a smaller impact.

To see how it’s impacting your keyword data
Avinash Kaushik (of Google Analytics) has a quick tip for checking to see how much this change is affecting your data (basically: for the affected time period, take the number of “not reported” and divide it by the total number of organic search referred traffic to get the percentage). In his postscript, Avinash even provides a one-click method for creating a custom report in your dashboard to track this piece of data.

What does it mean for you and what can you do?
There’s not really anything you can do to get the missing granular data back. This is NOT a limitation of the Google Analytics product; it impacts all analytics programs since Google is preventing this data from being passed by the browser.

What does it mean? Well, depending on how big that percentage of impacted traffic is, it probably won’t change anything for you.

I want to reiterate: you still know how many visits came from organic search and what your landing pages are for organic search traffic, so unless you’re doing keyword-level conversion analysis, you likely still have enough data to keep using analytics the same way as before.

The change may mean data on how search engine users are finding your website might be a bit fuzzier. It does NOT mean that the makeup of your organic search traffic has changed or will change; it does not mean you’re getting fewer search visitors or that your tactics for getting/maintaining search engine visibility should change. With the data that’s still being reported by logged-out users, you should still have a pretty good sense of what keywords are driving traffic to your site across the board.

You can still use your Google Webmaster Tools account to get impression and click-through data (although that data tends not to be very exact) if you just want a fuller picture of what’s happening with your site in the SERPs.

More background and further reading
There is, naturally, a lot of controversy about what Google is doing. Here’s Danny Sullivan’s opinion about why Google’s move to do this is a bad one:

If you’re interested in the bigger picture and more analysis of the situation, there are a lot of links to related articles at the bottom of Danny’s piece.

I’ll keep you updated if anything changes with regard to Google’s implementation. In the mean time, feel free to let me know if you have any questions (or if you are noticing that your site's "not reported" percentage is becoming significant).