A post appeared on Search Cowboys last month claiming that Universal Search was now trackable by Google Analytics thanks to somebody's eagle-eyed discovery of the URL parameter oi=value.

Traffic from the following sources was supposed to be directly measurable:

• Blog search
• Image search
• Spelling corrections                                                
• Sitelinks                                             
• Definitions                              
• Suggestions

So, that all sounds great.  Actionable data, hoorah!  And it might seem a valid method too, considering that if you look at the destination URL of these links you will see a value for the oi parameter specific to each Universal Search component.

The problem is, in reality, it doesn't actually work quite this well (as a tweet from @tomcritchlow reminded me this week).

A simple way to see this is by following one of these links to a website, typing  javascript:document.referrer into the address bar, and hitting 'enter'. The result will be the same URL tracked by Google Analytics.  For many of the examples, you'll be left asking, "OI! where did the oi parameter go?" Well it appears that our friend oi doesn't always live to tell the tale.

1. Search Google for 'cats', click one of the Universal Image results, and then execute javascript:document.referrer in the address bar.  No oi=.
2. Search Google for 'cats', click one of the Universal Blog Post results, and execute javascript:document.referrer in the address bar.  No oi=.
3. Do the same for Universal News, Universal Video, Universal Local, Universal Definitions, Sitelinks, and you'll find no oi=.

So, where does this work?  The proof is in the pudding at Search Cowboys - the screenshot included shows some examples where this filter does work. 

1. Revisions.  Search for 'cats', click the 'cats for sale' suggestion, and you'll see revisions_inline=cats+for+sale in the address bar.  Keep an eye out for revisions_narrow, which are similar but wedged in between regular search results.
2. Spelling corrections.  Look for the oi=spell in the address bar when you Google 'seomooz'.

Sadly, this discovery wasn't quite as useful as first thought.  Looking at some other parts of the screenshot, the blogsearch_group results actually refer to standard Google Blogsearch queries, so that isn't really universal search; more like vertical search.

One that I can't test is blended, which apparently suggests access from a mobile device.  Any smartphone users care to lend a hand? 

PS. You may be interested in reading this related article about using Google Analytics to learn more about the performance of your Sitelinks.