It's extra work for website owners to build/test/maintain opt-out functionality. Have you considered offering a pre-built opt in/out widget which can be re-styled and integrated easily?

Or you could even just provide website owners with a "global opt-out" URL that they can stick in their footer.

This link is a global opt-out :)

We don't want anyone on the platform who isn't aware/comfortable with it. Our instructions to the websites (when they join) are to create a link to the opt out page. I supposed it could be a direct opt out

It seems one of the biggest business issues is site visitor perception. I have a couple questions please.

What's your opt-rate rate so far out of the sites that have shown this option?

do you have any real data regarding hidden cost to a site visitor? like power consumption A/B testing or something?

The opt out rate has been close to 0, but (in all fairness) that has been due to the way websites choose to display it.

A standard for how to display might be called for, perhaps?

What do you mean? Unused cycles makes no sense. I'd be really annoyed if my laptop's battery life drops from 5 hours browsing the web to 1hour because it is running at 100% all the time due to this.