Add UTM parameter based on events

Question

I know that it's best to add Google Analytics UTM parameters externally for incoming campaign traffic.

However, when dealing with a juggernaut of an IT team who like to say "no" a lot I'd like to attempt to arm myself with a solid response. Analysts will feel my pain in trying to convince others to track campaigns the correctly, rather than by listening to a non analytics users advice of just creating segments based on URLs.

There will be a campaign running where a visitor to the website will input a promo code in order to get a free thing.

For whatever reason we cannot tag the incoming traffic or the links that will lead from the promo source with our UTM parameters.

I can create an event in GA for when a visitor enters a promo code that relates to the campaign in question - the URL generated will contain the promo code int he URL, thus allowing me to create an event.

Is it possible in Google-Analytics, combined with a lateral thinking developer, to overwrite the UTM parameters based upon a click event halfway through the visitor session? Could a script do this?

Any other ways around it?

We do have Google-Tag-Manager at our disposal too.

Answer 1

Doug,

Sorry to dissapoint you, but any overwriting based on events (or any single-hit action by user) won't work correctly and would lead to skewing your data anyway. See this brilliant post by Joshua.

What you could do however is to use CustomVar or CustomDimension (on session level probably), which would substitute UTM parameters. So if there is a promo on your werbsite, you can assign some value after users click on it.

Then by building a custom report, you should be able to use this with no restrictions, just instead of medium/source pick your customvar/customdim.

Hope this helps.