Here’s a brief post on searching for contact information on LinkedIn. Posting visible contact info on the profiles is discouraged; but, as we know, many members do, particularly those who are Recruiters, Sales, and “Open Networkers”.
At the same time, LinkedIn quietly takes some measures for us to see less of that contact info.
As an example, a search for “gmail.com” in the UK population returns about 250 results, while an X-Ray for “gmail.com” returns “About 3,570 results” and shows about 700. Sure enough, there may be false positives in the X-Ray, but it’s easy to locate some profiles found in X-Ray that are not included in the above LinkedIn internal search. If you are still in doubt, here is a more narrow search; compare internal search vs. X-Ray for the London, UK Area.
Here is another interesting example, showing the same tendency. Search for “com” in the last name, narrow to a the Greater Chicago Area; compare Internal search (under 200 results; 3 more if you search in the first name field) vs. X-Ray (About 460 results).
The moral of the story is that X-Raying for gmail-based email addresses and, possibly, anything else that points to an email address included in the profiles, would bring much better results than internal search.
As a side note, there’s quite a bit of other interpretation going on in the LinkedIn internal search, which didn’t use to happen. Somehow the internal search often recognizes keywords that sound like last names and would interpret the search as if you put the keyword in the last name field. That means that profiles mentioning someone by name would not be found. More on that later…