https://developers.google.com/analytics/devguides/collection/gajs/gaTrackingCustomVariables
"...Use a slot matrix to track large numbers of custom variables..."
How to implement it?
1 Answer
It's talking about a matrix of slot number vs page visited, and avoiding collisions between page/session/visitor level variables.
Example: Let's say you have 6 variables you want to track. You only get 5 slots (for free) so you need to re-use a slot. However, if you use the same slot on the same page then only the last value to be set on that slot is counted and the other is ignored.
To get around that you can set different variables on different pages in the same slot. For example on your blog posts you might want to set category=opinion but on your forum you wouldn't need that variable so you can re-use the same slot for a different variable like loggedin=true.
Similarly, if you track a variable at the page level but on a subsequent page set a session level variable in the same slot, it will overwrite the page one. (See the examples on the link you posted.)
So by "slot matrix" it basically means to make a chart or log of what variables are set at what points on the site, so that you can avoid clashes. If you really need to track a lot of variables you would probably be better off paying for Google Analytics Premium.
answered Jun 5, 2013 at 17:16
