[Jare]

You don't have to assume your user wants to be A/B tracked, or wants to purchase anything. You can allow the user to enable them nicely and non-intrusively without a popup. You can ask the user intrusively when they actually initiate a purchasing action.

Most sites choose do popup instead because (they think) it is more effective. So be it, but don't say it's "mandatory" or that "they are forced to".