Enhanced Ecommerce - How to track cart quantity update?
The documentation of the Enhanced Ecommerce plugin doesn't say a word on how to deal with the user changing the quantity of a line in their cart.
There are multiple solutions for this, but each of them has some serious drawbacks:
1) Calculate the difference and add or remove that.
2) Remove the line and then add with current quantity.
Method 1 has the advantage of passing the (most) correct user interaction. Since add/remove doesn't seem to have a nonInteraction parameter, using method 2 would mean wrong numbers of adds/removes.
Method 2 has the advantage of being able to change the price if a price change has happened after the product has been added the first time. For example: after adding more units the customer now has a lower unit price. Using method 1 would mean that either the amounts in GA are incorrect, or you would have to calculate price differences and fictionally give the latest added units a lower price.
Which of the two methods is preferable?