At the very least, I have to pay for it with my time, which is unrecoverable. If I can skip or otherwise ignore an ad, that is one thing, but forced interstitials is even more nebulous than a banner ad.
It's not free if I have to spend time servicing your revenue stream, unless you reimburse me at my market rate for my time that you spent/wasted.
It's not free if I have to spend time servicing your revenue stream, unless you reimburse me at my market rate for my time that you spent/wasted.