wikipedia has done a lot of research on this. Their method doesn't block content, doesn't force the user to interact with a dialog, and isn't perennial.
If the website is honestly just a bunch of scraped content which solely exists to solicit donations then go ahead. But if there is another purpose, any other one, than the popup dialog detracts from it in an unnecessarily injurious way.
If the website is honestly just a bunch of scraped content which solely exists to solicit donations then go ahead. But if there is another purpose, any other one, than the popup dialog detracts from it in an unnecessarily injurious way.