This is part three of a four-part series on how to use Google Analytics to track Telephone Leads.
Part one described the overall call tracking system. Part two explained how the data can appear in Google Analytics. Part three (this one) will start on the technical side and explain how to get the phone numbers on your site to switch according to the route to site the visitor has taken.
The final part, yet to be written, will explain how to get the data from the telephone call into Google Analytics (this is the CallTrackID bit).