How should I track events (efficiently) ?

I'm trying to track how many people scanned one of my QR codes. The way I do it is to make the QR code point to a specific redirect page that processes all the parameters and invokes Piwik PHP tracking API and then redirect the user to the correct page.

I'm seeking advice on what tracking action I should register with Piwik. From my understanding I'll surely be using CustomVariables for recording information about my QR code, but should I record the action as an outlink or just a pageview? What are advantages / disadvantages of one approach over the other? Thanks